Guardian PowerVent Training Manual. Flammable Vapor Ignition resistant (FVIR) compliant PowerVent water heater manufactured after 1 January 2006

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2 Guardian PowerVent Training Manual Flammable Vapor Ignition resistant (FVIR) compliant PowerVent water heater manufactured after 1 January 2006 Table of Contents INTRODUCTION... 3 SAFETY... 3 COMPONENTS OF A GUARDIAN POWERVENT WATER HEATER... 5 DEFINITIONS... 9 LOCKOUTS SEQUENCE OF OPERATIONS TIMING AND SETTINGS DIAGNOSTIC FLASH CODES HOW TO INTERPRET THE FLASH CODES HOW TO CHECK THE VACUUM SWITCH HOW TO CHECK THE THERMISTOR (TEMPERATURE SENSOR) HOW TO CHECK THE ECO (ENERGY CUT-OFF) HOW TO CHECK THE GAS CONTROL VALVE HOW TO CHECK THE VENT OVER TEMPERATURE SAFETY SWITCH HOW TO CHECK THE IGNITOR HOW TO CHECK THE ELECTRONIC GAS CONTROL HOW TO CHECK THE FLAMMABLE VAPOR SENSOR CONNECTION DIAGRAM TROUBLESHOOTING TABLE HOW TO REMOVE THE GUARDIAN POWERVENT INNER ACCESS DOOR HOW TO REMOVE THE GUARDIAN POWERVENT PILOT IGNITER ASSEMBLY HOW TO REMOVE THE GUARDIAN POWERVENT GAS CONTROL HOW TO REPLACE THE GUARDIAN POWERVENT VENT OVER TEMP SWITCH HOW TO REPLACE THE GUARDIAN POWERVENT VACUUM SWITCH HOW TO REPLACE THE GUARDIAN POWERVENT ELECTRONIC CONTROL MODULE HOW TO REPLACE THE GUARDIAN POWERVENT FLAMMABLE VAPOR (FV) SENSOR RESET PROCEDURES FOR INVENSYS CONTROL WHITE RODGERS GAS VALVE RESET PROCEDURES FOR WHITE RODGERS CONTROL Index of Tables Table 1 Time and Temperature to Produce a Scald... 3 Table 2 Sequence of Operations Table 3 Timings and Settings Table 4 Diagnostic Flash Codes Table 5 FV Sensor Values Page 1

3 Table 6 Venting the Guardian PowerVent Table 7 Guardian PowerVent Troubleshooting Table Index of Figures Figure 1 Components of Guardian PowerVent Burner Assembly... 7 Figure 2 Components of a Guardian PowerVent Water Heater... 8 Figure 3 Wiring Harness Connection Diagram Figure 4 Flash Code LED Figure 5 Blower Motor Figure 6 Vacuum Switch Figure 7 Thermistor and ECO Check Figure 8 FV Wiper Gas Control Figure 9 Vent Over Temperature Safety Switch Figure 10 Ignitor Assembly Figure 11 Gas Valve Connections Figure 12 Flammable Vapor Sensor Check Figure 13 Connection Diagram Figure 14 Invensys Reset Procedure Figure 15 White Rodgers Control Gas Valve Figure 16 White Rodgers Connection Diagram Before inspecting, diagnosing, repairing or operating any water heater, be sure to examine all of the safety and warning labels on the tank. Follow the instruction on these warning labels. Read and understand the Use and Care Manual that was shipped with the water heater. Failure to do so can result in unsafe operation of the water heater resulting in property damage, bodily injury, or death. Should you have any problems reading or following the instructions in the Use and Care Manual, seek the help of a licensed and qualified professional. NOTICE: This unit is equipped with a Flammable Vapor Sensor. Venting installation of this flammable vapor ignition resistant water heater involves the use of PVC glue. PVC glue emits flammable vapors. Do not apply power until enough time has passed to allow the vapors from the PVC primer and cement to dissipate. Installation in locations with ambient air over 100 degrees F may lock out the controls. Copyright 2008, Rheem Manufacturing Company, Water Heater Division. Page 2

4 INTRODUCTION This is a training manual not a job site service manual, nor a parts manual. The intent of this manual is to train users of PowerVent water heaters. This manual does not assume any particular user liability, skill level, experience or expertise. The terms and component parts used in this manual are current manufactured items or vendor provided items used in Rheem PowerVent gas water heaters, whether natural or liquid petroleum (L.P.). Exercise care when installing and repairing gas water heaters. Finally, we encourage all users to exercise good common sense and check your local plumbing, electrical and gas building codes. SAFETY FLAMMABLE LIQUIDS AND VAPORS Gasoline, as well as other flammable material and liquids (adhesives, solvents, etc.), and vapors they produce are extremely dangerous. DO NOT handle, use or store gasoline or other flammable or combustible materials anywhere near or in the vicinity of a water heater. The spark ignition and burner assembly in the water heater controls can ignite these vapors. Failure to do so can result in property damage, bodily injury or death. WATER TEMPERATURE ADJUSTMENT Safety and energy conservation are factors to be considered when selecting the water temperature setting on the thermostat. Water temperatures above F can cause severe burns or death from scalding. The chart shown here may be used as a guide in determining the proper water temperature for your home. Table 1 Time and Temperature to Produce a Scald Page 3

5 There is a hot water scalding potential if the thermostat is set too high. The temperature of the water in the heater is regulated by the adjustable thermostat located inside the control enclosure. Be sure to read and follow the warnings outlined on the warning label. This label is located on the water heater. To comply with safety regulations the thermostat was set at 68 0 F before the water heater was shipped from the factory. Households with small children, disabled, or elderly persons may require a F or lower thermostat setting to prevent contact with HOT water and potential scalding. ELECTRICAL SHOCK - Troubleshooting and repairing a PowerVent water heater can expose you to electrical shock. Some of the diagnostic procedures require the presence of 120 volt AC electricity. Use extreme caution when performing these procedures. When replacing an unserviceable component, turn off all power to the water heater and check for the presence of power with a multimeter or test lamp. The pilot electrode and ignition cable carry more than 10,000 volts of electrical energy. Use extreme caution when diagnosing the PowerVent. AUXILIARY CATCH PANS - The water heater should not be located in an area where leakage of the tank or connections will result in damage to the area adjacent to it or to lower floors of the structure. When such areas cannot be avoided, it is recommended that a suitable catch pan, adequately drained, be installed under the water heater. The pan must not restrict combustion air flow around the bottom of the heater. Auxiliary catch pans must conform to local codes. 18 INCH WATER HEATER STANDS Because of natural air movement in a room or other enclosed space, flammable vapors can be carried some distance from where liquids which give off flammable vapors are to be used or stored. The open flame of the water heater s pilot or main burner can ignite these vapors and create a shut down condition of the water heater which will not allow the water heater to ignite until examined by a Qualified Service Technician. If local codes require the use of a stand kit to Page 4

6 raise the water heater 18 above the floor, please contact the store where the water heater was purchased, or any water heater distributor. These kits must comply with local codes. The 2002 National Fuel Gas Code reads as follows: Installation in residential garages Gas utilization equipment in residential garages and in adjacent spaces that open to the garage and are not part of the living space of a dwelling unit shall be installed so that all burners and burner ignition devices are located not less than 18 in. (460mm) above the floor unless listed as flammable vapor ignition resistant. The 2003 International Fuel Gas Code has also been changed to reflect the exception: Elevation of Ignition Source: Exception: Elevation of ignition sources are not required for appliances that are listed as flammable vapor resistant and for installation without elevation. Residential Guardian PowerVent Certification Standards The Guardian PowerVent meets the following manufacturing, certification, energy efficiency and Low NOx standards: ANSI Z manufacturing and flammable vapor resistance standard CSA 4.1a-2000 Certification standard for North America National Appliance Energy Conservation Act Energy efficiency standard South Coast Air Quality Management District Low NOx emissions standard COMPONENTS OF A GUARDIAN POWERVENT WATER HEATER Anode Rod Rod made of a magnesium alloy that aids in the cathodic protection of the inner tank through the control of electrolysis. An anode rod can be made of any material that is more negative than the steel of the tank. Anti-Siphon Hole A small hole located in the dip tube approximately six inches from the top. The anti-siphon hole is designed to prevent the siphoning of water through the cold water line in the event of a loss of water. Blower Motor Assembly Electric motor that mechanically induces the proper draft for venting combustible gases. Also actuates the vacuum safety switch. Burner Assembly Metal fluted burner plate, igniter, pilot supply tube, main burner supply tube and door with gasket that disperses the main gas supply for ignition. The burner assembly provides the flame and heat to the water heater. There is a different burner assembly for propane gas and natural gas. Burner Access Door Metal door with burner assembly attached. Provides pathway for igniter wire, pilot and main supply gas tube and sight glass window. Connects to combustion chamber with Torx #20screws. Burner Door Access Gasket Gasket used to seal the inner door to the combustion chamber to prevent the escape of flammable vapors. Burner Supply Tube Supply tube that carries the most gas to the burner plate. Page 5

7 Cold Water Inlet Supply pipe that delivers cold water from the main supply to the water heater. Combustion Air Inlet Openings Air pathway on the outer jacket with small holes. The holes are designed to trap lint, dust and oil that would naturally accumulate inside the combustion chamber. Aids in a cleaner main burner flame pattern. Dip Tube Non-metallic tube extending from the cold water inlet to a predetermined area of the tank near the bottom of the tank that feeds water into the system. The length of the dip tube will vary from product to product. Drain Valve Valve used to drain the hot water when performing periodic cleaning or replacing a part. Flue Device that carries the combustion air from the combustion chamber and discharges it the venting. Flue Baffle Device that retards air movement through the flue. Keeps the heated combustion gases in the flue longer for maximum heat dispersion to the tank water. Flame Arrestor Plate - Perforated metal plate inside the combustion chamber. If a flammable vapor event occurs, this plate allows the vapors to burn (much like a candle) on the surface of the plate. This prevents the ignition of flammable vapors outside the water heater. Floor Shield Metal plate between the arrestor plate and the tank bottom of the water heater. This plate protects the flame arrestor from falling debris and prevents it from accumulating on the arrestor plate. Foam Insulation Insulation between the steel tank and the outer jacket that helps prevent heat loss to the ambient atmosphere. Flammable Vapor Sensor The sensor located just below the outer door to the combustion chamber that continuously monitors for the presence of flammable vapors. This is a one time use sensor. Gas Control Valve Integrated electronic control module and gas valve that takes the unregulated main supply gas and regulates the gas for use by the water heater. Also contains the electronic control module for the operation of the product. The control is responsive to flame properties, sensing the presence or absence of flame, and in the event of ignition failure or unintentional flame or flame extinguishments, forces the safety shutdown. The gas control valve also contains the thermostat that controls the temperature of the water, the high limit safety switch and the flammable vapor sensor controls. High Limit (ECO) Switch (Energy Cut Off) - Safety device located on the thermostat that shunts all power to the control module if the temperature of the water in the tank becomes excessive. The ECO will trip off at approximately 200 degrees Fahrenheit. Hot Water Outlet Supply pipe that delivers the hot water to the faucets. Inner Tank Steel tank with a porcelain enamel (glass) lining that stores the hot water. Outer Jacket Thin metal outer shell of the water heater. Pilot / Igniter Assembly The sparking device designed to ignite the pilot and main burner when the thermostat demands heat. Sometimes referred to as the spark ignitor. Pilot Supply Tube Supply tube that carries the pilot gas to the pilot hood and ignitor. Sight Glass Glass window on the inner door allowing visual inspection of the combustion chamber. Shut off Plate Combustion air inlet plate located on the bottom of the combustion chamber. It allows combustion air into the chamber. When the thermal release device trips, this plate will close and suffocate any flames inside the combustion chamber. Page 6

8 Thermal Release Device (TRD) Mechanism that detects and trips in the presence of high heat inside the combustion chamber. This higher than normal heat could mean a flammable vapor incident or the creation of carbon monoxide. Temperature and Pressure Relief Valve Safety device that vents extreme pressure and exceedingly hot water outside the tank to prevent tank rupture and explosion. Commonly called the T&P valve, it is designed to operate at approximately 150 PSI or F. Vacuum Switch Safety device that will allow power to the gas control module. Senses the presence of vacuum from the blower motor to verify proper venting before it opens the gas valve. Figure 1 Components of Guardian PowerVent Burner Assembly Propane Natural Page 7

9 Figure 2 Components of a Guardian PowerVent Water Heater Page 8

10 DEFINITIONS Automatic Restart Time - The period of time between a lockout and the automatic action to initiate another ignition period. (60 minutes) Flame-Establishing Period - The period of time between initialization of gas flow and proof of the supervised flame. (also called flame rectification) Flame Failure Response time - The period of time between loss of the supervised flame and the action to shut off the gas supply. (The time it takes for the flame rectification circuit to realize there is no flame and the control module shutting off the gas valve.) Ignition Attempts - Number of attempts in a single call for heat to ignite the gas before locking out. The number of attempts will be zeroed if there is proof of flame for more than 10 seconds. (3 ignition attempts) Ignition Activation Period - The period of time between energizing the gas valve and deactivation of the ignition source during a trial for ignition period. Ignition Recycles - Number of attempts in a single call for heat to initiate gas flow if proof of flame has been established and is then lost. (3 ignition attempts) Lockout - The automatic action to end an ignition sequence. Reinitiating another ignition sequence may require a manual operation (reset). Pilot Flame Establishing Period - The period if time between initiation of pilot gas flow and proof of the supervised pilot flame. Purge time - The period of time intended to allow for the dissipation of any unburned gas or residual products of combustion. o Pre-purge Time - The purge time which occurs at the beginning of heat cycle prior to initiating ignition. o Inter-purge Time - The purge time that takes place between the end of trial for ignition period and reactivation of the ignition source on the multi-try system. o Post-purge Time - The purge time which occurs at the end of a heat cycle. Recycle Time - The period to time between shut-off of the gas supply following loss of the supervised ignition source or the supervised main burner flame and the reactivation of the ignition source. Set Point - A selectable temperature set by the user. Temperature selection is made by rotating the red knob on the face of the gas control valve. Temperature Differential - The temperature difference between when the thermostat is satisfied and a call for heat. Usually expressed in +/- from temperature setting. Trial for Ignition Period - The period of time between energizing and de-energizing the gas valve, if proof of supervised flame is not established. Valve Sequence Period - The sum of all trial for ignition periods prior to lockout, if proof of the supervised flame is not established. Page 9

11 LOCKOUTS Internal Lockout - As the control performs its various control checks of the microprocessor s function and feedback circuitry it detects a fault condition. The control will respond by deenergizing all outputs and entering a lockout. The control will lockout if a failure is detected within the control or it recognizes flame when none should be present. The LED will be turned Steady On and all other inputs will be turned off. The control must be manually reset by cycling the line voltage. External Lockout - The control will lockout if it failed to ignite gas after the specified number of ignition attempts (3) or detected improper states of safety switch (ECO or vent over temp switch). The green led will flash a code to indicate the type of failure. (See LED chart). The blower motor will be turned on if flame is detected and all other outputs will be turned off. The control must be manually reset by cycling the line voltage. LFL Lockout (Lower Flammability Limit) The control shall lockout if it senses the LFL Fault signals from the sensor. The control shall respond to LFL fault in the following manner: The main valve, pilot valve and spark igniter shall be de-activated. The LED error code for the Flammable Vapor present Condition shall be displayed. The inducer blower shall be energized for the Post-purge time at the beginning of lockout. The control shall remain in lockout until external LFL Lockout Reset is resolved. Once the control detects Lower Flame Limit (LFL) Fault signal, the control will de-energize main valve, pilot valve and spark igniter, and enter the LFL lockout. The inducer blower shall be energized for the Post-purge time of 30 seconds at the beginning of lockout. The control shall output the corresponding error code to diagnostic LED. If the LFL senses a miswired condition, such as a shunt or plug, the control shall output the corresponding code to diagnostic LED. Figure 3 Wiring Harness Connection Diagram Page 10

12 SEQUENCE OF OPERATIONS All voltage inputs are 120V. Neither a surge protector nor GFI circuit is recommended or required. All electrical connectors are Molex and fit one way. The word control in this sequence will normally refer to the electronic control module on the gas valve. The control constantly monitors the water temperature via the thermistor so that the water temperature is within the user-selected temperature range. Control monitors the inputs for any fault conditions and presence of flammable vapors. If Call for Heat has not initiated for more then 6 hours, the control will automatically decrease the differential by 5 F. If the temperature is still not less than the set temperature minus differential, the control continues in Stand-by mode. Tank is cold and full of water. Gas supply is connected. Gas valve is set to ON position. Unit is plugged into a 3- prong plug. Unit is polarity sensitive. Turn temperature dial down to LOWEST position. Turn rocker switch to ON position. Fill tank. Connect gas. Turn valve ON. Must be plugged into a 3-prong wall socket. Socket must be wired polarity correct. Black wire to brass screw; white wire to silver screw. Rocker switch controls all power inputs to blower motor, gas valve, and control module in gas valve. You will always have 120V at the red #3 wire. At power ON and a demand for heat, the control performs a self-test diagnostic routine. If the self-check fails, the control locks out with a solid ON LED light. Page 11

13 Turn temperature dial to temperature selection. The white triangle next to WARM is the 120-degree setting. Temperature is sensed electronically by the Thermistor in the sensing bulb. It is the two white wires at the RED Molex connector. (See Fig 3 on page 10.) Initiates a call for heat. 120V power is passed from the red #3 wire thru the control to the yellow #5 wire and to the blower motor. This is the only source of AC power for the blower motor. (1st Safety) Control checks for OPEN vacuum switch. You will have 120V at the blue #8-vacuum switch wire. Note: The over-temp switch in the blower is wired in series. If the vent temp exceeds F, then the over-temp switch will activate. LED will flash 3/3. In normal operation, the switch is OPEN at beginning of call for heat. If no blower motor, then check: 120V power at the #5 yellow wire Vacuum switch tubing Vacuum switch Vent over-temperature switch is not activated If vacuum switch has failed in the closed position, the control attempts to open the switch by cycling (turning off blower, then on) the blower motor. After 5 cycles (attempts), the control will lockout. LED code is 3/1. Page 12

14 (2nd Safety) Control turns on blower motor. This creates enough venting to close the vacuum safety switch. Blower is in pre-purge stage for about 15 seconds. You will have 120V at the yellow (#5-blower motor) wire. If you hear spark, then there is 120V power at the yellow #5 location. Ignition attempt Spark ignitor begins to spark. (Orange wire) 120V voltage opens pilot vein of gas valve. You will have 120V at the yellow #7 pilot valve wire. In normal operation, the control checks for a closed vacuum switch within 12 seconds before starting the pre-purge time. The vacuum switch measures the vacuum created by the blower and verifies the blower is operating at speed. The control attempts to close the switch by cycling (turning off blower, then on) the blower motor. After 5 cycles (attempts), the control will lockout. LED flashed 3/3. Listen for spark ignitor. Visually verify spark at the pilot electrode. Check to make sure the valve is turned ON. Check for voltage to the pilot valve yellow #7 wire connection. Visually verify pilot flame is present. (3rd Safety) Flame is rectified. Pilot lights. After pilot flame has been recognized (rectified), the spark will stop Main valve is energized. Note: There is always a flame rectification circuit check while the main burner is operating. When the main burner fails, the unit will recycle and attempt ignition. Page 13

15 Main valve on gas valve opens. You will have 120V at the blue #6 main valve wire. Main burner ignition. The flame rectification circuit is constantly ON during pilot and main burner. If the control module thinks flame is suppose to be present, then the circuit constantly looks for the presence of flame. Water heats to thermostat setting. (4th Safety) Blower motor thermal safety switch is monitoring venting temperatures. Flammable Vapor (FV) sensor is monitoring. The trial for ignition will last for 75 seconds. If the control is not able to establish a pilot flame, it will initiate the inter-purge. This is a 30 second purge without spark or gas to clear the combustion chamber. Then the unit will retry for ignition. The unit will try 3 times total for ignition. If ignition fails, it will initiate a post-purge (30 seconds) to clear the combustion chamber; then go into lockout. LED flashes 1/1. Check for 120V power to the main valve (blue wire) side of the gas valve. If the unit rectifies flame for at least 10 seconds, the internal counter resets to zero. If the flame is established and then lost, the control will turn off the main and pilot valve, execute an inter-purge (30 seconds) and then start a new trial for ignition sequence. ECO is monitoring water temperature. Blower motor thermal safety switch set to 180 F with automatic reset. FV Sensor is monitoring local environment for presence of flammable vapors Page 14

16 Water is heated. Thermostat and control module shuts off all power to the unit. Unit is in stand-by mode. (The electronic control checks to see if the water temp is close to the set point. If so, it will attempt to turn the main burner on. For instance, if the set point is 120 0, then after 6 hours, the control module will adjust the set point back to to see if it can fire off the main burner.) Unit is in Stand-by mode In stand-by mode, the control module constantly monitors the water temperature via the thermistor to ensure the water inside the tank is within the user-selected range. In addition, the control will monitor the inputs to look for any other fault conditions such as a control health, false flame or faulty switches. Unit monitors control health and the local environment for flammable vapors as long as there is 120 VAC to the water heater. False sensing The blower will turn on immediately if flame is sensed when no flame should be present. Flame with gas valve off - If there is proof of flame for 10 seconds with the gas valve off, the control will go into lockout. The blower motor will run during lockout if there is proof of flame. If there is proof of flame for less than 10 seconds, the unit will postpurge. LED flashes 4/3. Page 15

17 ECO High Limit:(>200 0 F) The high limit switch opens after flame is established. That means the water in the tank got over F. Table 2 Sequence of Operations The pilot valve, main valve, and spark ignition are turned off, but the blower will remain on. LED flashes 4/2. The ECO has a one-time use. N O T E S Page 16

18 TIMING AND SETTINGS Unless otherwise noted, all nominal functional timings are to be accurate to ± 1 second or 5%, whichever is greater, over the specified operating temperature and voltage ranges Timing/ Setting Nominal Temperature differentials (factory pre-set) 15 Temperature set point range Flame Establishing Period 2 Seconds Flame Failure Response Time 2 Seconds Recycle Time 15 Seconds Lockout Time pre-purge time in Seconds Vacuum switch short cycle 9 Seconds Vacuum switch long cycle 12 Seconds Pre-purge time (factory pre-set) 15Seconds Inter-purge Time 30 Seconds Post-purge Time (factory pre-set) 30 Seconds Ignition Activation Period 75 Seconds Trial for Ignition Period 75 Seconds Valve Sequence Period 225 Seconds Automatic Restart Time 60 minutes Number of ignition trials 3 times / trails Table 3 Timings and Settings DIAGNOSTIC FLASH CODES Another new feature of the Guardian PowerVent is the LED diagnostics system built into the control module. When the unit faults, the LED will flash a certain number of times. A flashing green LED diagnostic code indicates that a sequence of events has forced a lockout condition and is in a lockout state. Number of flashes indicates the type of failure. The flash code or number of flashes will occur followed by a pause before it repeats. Any power interruption of more than 2 seconds with the reapplication of power, will re-set the controls. If a fault condition existed prior to the reset, the fault condition will clear with the exception of the FV sensor codes. If the fault condition still exists after the application of power, the control will indicate the appropriate fault. Figure 4 Flash Code LED A green LED is provided to indicate system status. When a fault occurs within the water heater, the control will output a code using an LED. Page 17

19 The LED will have a variety of status conditions: ON is defined as constantly on with no blinking patterns. Slow Blink is defined as a one blink per second. Fast blink is defined as five blinks per second. There will be a 1 second period between primary and secondary pattern when LED will be off. (blink-one second-blink) After the secondary pattern completes, there will be a 3 second period when LED will be off before patterns repeat. (blink-one second-blink - - three seconds - - blink-one secondblink) System condition Primary pattern Secondary pattern Stand-by mode Slow blink None Call for heat present Fast blink None Internal control failure/ miswiring ON Solid None Ignition failure 1 blink 1 blink Flammable vapors present 2 blinks 1 blink Flammable Vapor Detector failure/ miswiring 2 blinks 3 blinks Vacuum switch fails to open 3 blinks 1 blink Vacuum switch fails to close 3 blinks 3 blinks Line/ neutral polarity failure 4 blinks 1 blinks ECO failure 4 blinks 2 blink False flame 4 blinks 3 blinks Vacation mode active 5 blinks None Table 4 Diagnostic Flash Codes HOW TO INTERPRET THE FLASH CODES Solid ON If the green LED is constantly on, then there is a problem with the internal controls (computer chip) of the gas valve. It can also mean the thermistor/eco is disconnected. Ensure all connections to the valve are tight and correct. Cycle the power to attempt to reset the control. Slow Flash - Flashing LED indicates normal operation of the controls. This also indicates the unit is in Stand-By mode and the water inside the tank is hot. There is always a slow flash when power is applied. If there is no LED, then check for unit plugged in. Check for power at the wall plug or other source of 120VAC. Verify 120VAC power at the red #4 wire. Fast Flash A fast flash indicates there is a call for heat. You should hear the blower motor running at a minimum. One (1) Flash / One (1) Flash Ignition Failure. This means there was no flame rectification of the pilot. Maximum ignition attempts made. This failure occurs when the control does not see proper ignition (flame rectification) given the allotted attempts and ignition cycles. (3) Remember, flame rectification is required before the unit will continue and open the main valve of the gas valve. The flame rectification circuit proves the presence of pilot flame at the pilot and Page 18

20 ignitor. The control will lockout if it failed to ignite gas after three (3) ignition attempts. Here is how it works: 1. Verify control valve is ON. 2. Verify there is gas to the valve. 3. Verify minimum gas pressure. 4. Check for 120V voltage to the pilot valve (yellow wire) connection at the gas valve. If voltage is present, replace control valve. 5. If voltage is not present then check for 120V at terminal #7 (yellow wire) and at #5 (yellow wire). If power at #5, but not at #7, then replace control. 6. If power at #7, check yellow wire and Molex connector to valve. Listen for the spark ignitor. If you do not hear spark, verify 120V at the red #4 wire on the control. Replace the control module. 7. If you hear spark, using insulated pliers, remove the orange cable from the control and reset heater. When you hear spark again, slowly move the orange wire terminal back to the control and verify spark with at least 1/8 inch gap. If there is no spark, replace the control. 8. If there is spark, but not at the ignitor, the check for proper spark gap between electrode and pilot hood. Replace ignitor. 9. If there is spark, then check for a pilot flame first. If there is no pilot flame, then check power to the pilot side (yellow wire) of the gas valve. 10. Check for gas and gas pressure. Two (2) Flash / One (1) Flash The FV sensor has detected a flammable vapor. There is no recovery from this fault code. The electronic control module and sensor must be replaced. Two (2) Flashes / Three (3) Flashes The FV sensor has malfunctioned is miswired. There is no recovery from this fault code. The electronic control module and sensor must be replaced. Three (3) Flashes / One (1) Flash The vacuum switch has failed to open. The control insures that the vacuum switch is open before it turns on the blower. If the control cannot force the switch to open by cycling the blower, it will indicate this failure. The vacuum switch is a safety device. Vacuum switch is normally open. The control checks to ensure the vacuum switch can open (safety position) before it starts its sequence. If the switch is closed and cannot be opened, the code will flash. Vacuum switch is closed and cannot be opened. 1. Turn heater off and remove wires to vacuum switch. 2. Measure continuity thru the switch. 3. If there is continuity, then replace switch. Three (3) Flashes / Three (3) Flashes - Vacuum switch fails to close. When the blower is turned on, the control insures it that the vacuum switch is closed before continuing with the ignition sequence. If it cannot force the switch to close by cycling the blower, it will indicate this failure. The vacuum switch may also fail or fault during main burner. If this happens, then you will get a flash code of four. If blower motor is operating at speed and there are no vacuum restrictions, a closed vacuum switch will allow 120V power to pass between the red (inbound) wire and the blue (outbound) wire. Blocked venting will be a primary cause of this failure. If Page 19

21 venting is blocked, then there is no power thru the vacuum safety switch to the control module and pilot valve. Venting over-temperature switch will be another cause of this failure. 1. Check for rubber vacuum hose and crimping. 2. Verify motor is running. 3. Verify PVC venting is free and clear or all obstructions. 4. Verify termination vent is free and clear of all obstructions. 5. Verify venting does not contain an excessive number of elbows. 6. Verify 120V at the blue #8 wire on the control. If no power, verify 120V at the black wire on the vacuum switch. 7. Verify vacuum safety switch is operating. Reset heater. Remove black wire from vacuum switch and measure for 120V. If no 120V, then verify.75 inches w.c. with a magnahelic gauge. Replace vacuum switch. 8. Verify over-temp safety switch is not open (too hot). If 120V at the black wire on the vacuum switch, but not at the blue #8 wire position of the control, then over-temp switch may be tripped. Cool switch to less than Four (4) Flashes / One (1) Flash - If the control senses the neutral has a potential with respect to earth ground, it will indicate this failure. On start up and power on, the control module looks for proper polarity. If polarity is reversed or not present, unit locks out immediately. There will be no blower motor or ignition attempts. 1. Incorrect polarity at the wall plug or power connection to the water heater. 2. Remove power strip or other GFI circuit and re-try. Four (4) Flashes / Two (2) Flashes ECO failure. If the control senses the ECO has opened, it will indicate this failure. Water temp has exceeded F. One time use ECO has tripped. Unit will cycle 3 times and then lock out with 4/2 flashes. During ignition sequence you will NOT have power to the yellow #7 wire to the pilot side of the gas valve. 1. Remove red Molex connector from control. 2. Verify continuity thru the red wires of the ECO/Thermistor Molex connector. 3. If there is no continuity, then ECO is tripped. Replace control. 4. If there is continuity, reinstall Molex and reset heater. Four (4) Flashes / Three (3) Flashes False flame. Indicated the control is sensing flame with gas valve OFF. The blower will turn on immediately if flame is sensed with the gas valve off. If there is proof of flame for 10 seconds with the gas valve off, the control will go into lockout. The blower motor will run during lockout if there is proof of flame. If there is proof of flame for less than 10 seconds, the unit will post-purge. Five (5) Flashes Indicates the thermostat dial is set to its lowest setting Vacation. There will be no calls for heat until the water temperature reaches 68 0 F. Page 20

22 HOW TO CHECK THE BLOWER MOTOR The blower motor on the Guardian PowerVent is responsible for all fresh combustion air entering the combustion chamber. There are two different blowers and may not be interchanged between products. The short blower goes on only short models and the tall blower and goes on the tall models. The tall blower is more robust than the other because is needs more power to vent the combustion by-products on the taller models. Interchanging the two motors will cause erratic behavior and lockouts. Of special note is that the blower motor mounting gaskets must be in good condition to prevent exhaust gases from escaping into the living space where the water heater is installed. In normal operation, the controls check for a closed vacuum switch within 12 seconds before starting the pre-purge time. The vacuum switch measures the vacuum created by the blower and verifies the blower is operating at speed. The control attempts to verify the vacuum switch is open first. If the vacuum switch is not open, the control attempts to open the switch by cycling (turning off, then on) the blower motor. After 5 cycles (attempts), the control will lockout. LED indicator will flash 3/1. This means the vacuum switch failed to open. When the blower is turned on, the control insures it that the vacuum switch is closed before continuing with the ignition sequence. If it cannot force the switch to close by cycling the blower, it will indicate this failure. LED indicator will flash 3/3. Three potential causes of these faults are the vacuum switch is damaged, the blower motor is damaged, or there are venting problems. Figure 5 Blower Motor 1. Verify unit is plugged in to a 120VAC source. 2. Disconnect the PVC vent pipe temporarily. 3. Turn unit on at the on/off switch at the blower motor. 4. Blower motor should operate. Check flash code on the gas valve. The LED should have a constant fast flash. If the blower motor comes on and you get main burner, there is a problem with the venting or a vent restriction. 5. If the blower motor does not operate, check for 120VAC at the on/off switch. 6. Remove the switch cover and measure for 120VAC at the bottom of the switch. If 120 VAC on the bottom, then turn switch to on and check for 120VAC at top of switch. If 120VAC at top of switch, then verify 120VAC at the red #3 wire on the control valve; then verify 120VAC on the yellow #5 wire. 7. If you have 120VAC at the yellow #5 wire, replace the blower motor. 8. If you do not have 120VAC at the yellow #5 wire, replace the control valve. Page 21

23 HOW TO CHECK THE VACUUM SWITCH At beginning of a call for heat, the vacuum switch is OPEN. If the blower motor is not working, then check: 1. Vacuum switch tubing is not kinked and connected. 2. Vacuum switch is connected with two red and black wires. 3. Vent over-temperature switch is not activated. 4. The control insures that the vacuum switch is open before it turns on the blower. If the control cannot force the switch to open by cycling the blower, it will indicate this failure. After 5 cycles (attempts), the control will lockout. LED Indicator will flash 3/1 times. Replace vacuum switch. 5. Next, the control insures that the vacuum switch is closed before it turns on the pilot and main burner. If the control cannot force the switch to close by cycling the blower, it will indicate this failure. After 5 cycles (attempts), the control will lockout. LED Indicator will flash 3/3 times. 6. Check venting for obstructions, then.. Assuming the blower motor is running Figure 6 Vacuum Switch 1. Verify 120VAC at the red wire to the bottom of the vacuum safety switch. (There should always be 120VAC at this wire, even when the unit is in stand-by mode.) 2. Measure 120VAC at the blue wire on the vacuum safety switch. 3. If there is no power at the blue wire, then verify blower motor draft of 0.75 inches w.c. with a magnahelic gauge. Replace vacuum safety switch if there is at least.75 inches w.c. Otherwise, replace the blower motor. HOW TO CHECK THE THERMISTOR (TEMPERATURE SENSOR) The temperature sensing mechanism is electronic; not mechanical. The thermistor is nothing more than a resistor installed in the temperature sensing bulb of the control valve. As the water temperature cools, the thermistor will increase its resistance value (in thousands of OHMS). The control module knows that a specific resistance value is equal to a specific water temperature. Eventually, the resistance value gets so high that is causes the electronic control module to demand heat and start a cycle. As the water is heated, the resistance value in the thermistor drops. The resistance value is based on temperature; so when the water gets to the proper temperature (a known resistance value), the control module ends the demand for heat. Eventually, the resistance value gets so high that is causes the electronic control module to demand heat and start a cycle. As the water is heated, the resistance value in the thermistor drops. The resistance value is based on temperature; so when the water gets to the proper temperature (a know resistance value), the control module ends the demand for heat. Page 22

24 Verify temperature calibration: Measure the resistance value of the thermistor by measuring between the two white wires of the red Molex connect. Make sure the connector is not attached to the control module or you will get a false reading. Verify thermistor is good with an Ohms resistance test. At room temperature, resistance is approximately 10.4 k Ohms (10,400 Ohms S). 1. Remove the red Molex plug. Measure the Ohms resistance value between the two white wires on the plug. 2. If there is no resistance at all, then replace the gas control valve. 3. If there is any resistance, then the thermistor is probably OK. The actual resistance during this Ohms check will be determined by the temperature of the water. If you introduce cold water into the tank, you will see a change in the resistance. Figure 7 Thermistor and ECO Check HOW TO CHECK THE ECO (ENERGY CUT-OFF) The ECO is a one time use safety device that trips at 200 F. Verify ECO is good by doing a continuity check between the two red wires at the red Molex connector. Continuity means the one time use ECO is not tripped. Lack of continuity means the one time use ECO is tripped. Replace the control valve. Remove the red Molex connector before conducting the continuity test. 1. Remove the red Molex plug. Measure the continuity between the two red wires on the plug. 2. If there is no continuity at all, then replace the gas control valve. 3. If there is continuity, then the ECO is OK. HOW TO CHECK THE GAS CONTROL VALVE Pilot Side of Gas Valve - Ignition attempt by the control board means you should be hearing the spark ignitor along the orange wire. Check to make sure the valve is turned ON. At the same time, 120V opens pilot vein of gas valve. You will have 120V at the yellow #7 pilot valve wire. If you have 120V and there is gas vacuum, then you must have a pilot flame. If not replace the control valve. The "trial for ignition" will last for 75 seconds. The unit will try 3 times total for ignition, it will initiate a post-purge (30 seconds) to clear the combustion chamber, and then go into lockout. LED indicator will flash 1/1 times. Figure 8 FV Wiper Gas Control Main Valve Side of Gas Valve - After pilot flame has been recognized (rectified), the spark will stop and main valve is energized. Check to make sure the valve is turned ON and you have a Page 23

25 pilot flame. You will have 120V at the blue#6 main valve wire. If you have 120V and there is gas vacuum and a pilot flame, then you must have main burner flame. If not replace the control valve. The control mechanism is a replaceable part. However, proper troubleshooting must be used to distinguish between the board and the gas valve mechanisms. The gas valve control board logic is proprietary to Rheem. Three times (cycles) and the valve locks out on the respective code. In some instances, the control will reset by cycling the power to the control valve. HOW TO CHECK THE VENT OVER TEMPERATURE SAFETY SWITCH Blower motor thermal safety switch (vent over temperature) is set to 180 F with automatic reset. It is wired in series after the vacuum safety, and before the control module. If the sensor does not cool, there will be no power to the blue #8 terminal on the control valve. Without power at the blue #8, the control module will not forward power to the pilot side of the gas valve. After cycling, there is no flame rectification and will force a lockout (1/1 flash Ignition Failure). Verify continuity through the thermal safety switch. IF no continuity, then switch is open. Cool the switch to reset. Figure 9 Vent Over Temperature Safety Switch HOW TO CHECK THE IGNITOR 1. Remove the on/off switch cover panel. 2. Disconnect the blue wire to the vacuum safety switch. 3. Disconnect the Molex plug. 4. Measure continuity along the blue wire from the spade terminal to the Molex plug. The vent over-temperature switch is a normally closed switch. You should have continuity. The switch is good. 5. If you do not have continuity, then cool the over temp switch. You can accelerate this process with a cold rag placed on the switch. Once the switch cools to less than 180 F, you will get continuity. If not, replace the switch. Checking the ignitor is accomplished by first listening for the sparking sound. It sounds like a rapid ticking. Listen for the spark ignitor. If you do not hear spark, verify 120V at the blue #8 wire, and then blue #6 pilot wire on the control. If you have blower motor and power, but do not hear the sparking sound, then replace the control module. 1. If you hear spark, then reset heater. Using insulated pliers, remove the orange cable from the control. 2. When you hear spark again, slowly move the orange wire terminal back to the control and verify spark with at least 1/8 inch gap. 3. If there is no spark, then replace the control. 4. If there is spark, turn heater off and verify continuity of orange wire. Page 24

26 5. Check ignitor gap of 1/8 inch between probe and hood. Check ignitor for cracks and other damage. Replace ignitor assembly Figure 10 Ignitor Assembly HOW TO CHECK THE ELECTRONIC GAS CONTROL Checking the electronic gas control is a function of power in means power out. If the unit is plugged into an electrical source and turned on at the on/off switch, then there is always power to the control module. Verify 120V at the red #3 wire position. If there is power at this location, then the control module is receiving 120VAC and must work. You should be hearing spark and have pilot and main burner. If you see a steady, solid green light on the LED, then the control has failed its internal self diagnostics. Each time there is a call for heat, the control module performs a self check. If it fails this check, then replace the gas control valve. Figure 11 Gas Valve Connections Page 25

27 HOW TO CHECK THE FLAMMABLE VAPOR SENSOR The Flammable Vapor (FV) Sensor can operate between 32 0 F and F with relative humidity between 10% and 95%. The sensor works by absorbing flammable vapors (or hydrocarbons) in a passive mode. It has a normal operating resistance value between 13k and 25k Ohms (thousand Ohms). Any material that emits a flammable vapor odor, such as gasoline, paint thinner, cleaning solvents, and glues may trip the FV Sensor. Figure 12 Flammable Vapor Sensor Check Table 5 FV Sensor Values FV Sensor Input Condition Normal operation FV Sensor failure FV Fault input status Input resistance 13K Ohm and 25K Ohm Input resistance 7K Ohm or 100K Ohm CONNECTION DIAGRAM Note: You will also find a copy of this connection diagram on the water heater. Figure 13 Connection Diagram Page 26

28 VENTING THE GUARDIAN POWERVENT This unit can be vented using only the following recommended pipe material. Use only 2- or 3- inch diameter pipe. The mixing of 2" and 3" vent pipe is not recommended. If 3" pipe is used, a 2" to 3" bell coupling is recommended at the rubber coupling. Installation up to 7,700 feet is possible with all models. You will not need to make any changes if you use 3 venting. If you use 2 venting, you will need to decrement the maximum vent length by 10 feet. PVC (Schedule 40, ASTM D-1785) CPVC (Schedule 40, ASTM F-441) ABS (Schedule 40, ASTM D-2661) Number of 2 inch 90 0 elbows with vent terminal Number of 2 inch 45 0 elbows One (1) None One (1) One (1) Two (2) None Two (2) One (1) Three (3) None Maximum 2 inch pipe length in feet Using 2 inch PVC For the 2 vent, one 90 elbow is approximately equal to 6 feet of pipe. One 45 elbow is approximately equal to 3 feet of pipe. Minimum vent length for 2 vent pipe is 1.00 foot of vertical pipe, one (1) 90 elbow, and 3.00 feet of horizontal pipe. Number of 3 inch 90 0 elbows with vent terminal Number of 3 inch 45 0 elbows One (1) None One (1) One (1) Two (2) None Two (2) One (1) Three (3) None Three (3) One (1) Four (4) None Four (4) One (1) Five (5) None Maximum 3 inch pipe length in feet Using 3 inch PVC For the 3 vent, one 90 elbow is approximately equal to 5 feet of pipe. One 45 elbow is approximately equal to 2.5 feet of pipe. Minimum vent length for 3 vent pipe is 1.00 foot of vertical pipe, one (1) 90 elbow, and 4.00 feet of horizontal pipe. Table 6 Venting the Guardian PowerVent Page 27

29 TROUBLESHOOTING TABLE NATURE OF TROUBLE No Hot Water Not Enough Hot Water Unable to light pilot (and I don t hear the spark ignitor) You may see one of the following flash codes: 1/1 3/1 3/3 POSSIBLE CAUSES 1. Electrical supply turned off 2. Gas supply turned off 3. Pilot does not light 4. Main burner does not light 5. ECO is tripped 6. Flammable Vapor Sensor trip. 1. Thermostat set too low 2. Burner orifice or burner plate is clogged 3. Low gas pressure 6. Thermostat out of calibration 7. Defective dip tube 8. Heater is undersized 1. Blower motor not operating 2. Vacuum switch damaged 3. Vent safety over-temp switch is tripped. 4. Spark ignitor is damaged. 5. Gas valve damaged. 6. Energy Cut-off (ECO) is tripped. WHAT TO DO Check fuse panel and on/off switch at blower motor. Verify proper continuity on wall plug (control will flash 4/1). Turn on gas supply; turn on gas valve. Check 1 and 2 above. Then see Unable to light pilot and Pilot does not stay lit. See Main burner will not stay lit. Verify ECO with continuity test. Replace electronic control module and sensor. Adjust thermostat. Inspect and clean orifice and burner plate. Check gas supply pressure and manifold pressure. Conduct partial draw test to verify thermostat. Verify thermistor with ohms resistance test. Check and replace dip tube. Adjust peak hour demand. Verify unit is plugged in and rocker switch set to ON. Control module will flash with 3/3. Check venting for restrictions. Retry or replace blower assembly. Exhaust gases exceeded 180 F. Check combustion chamber, blower motor area, and venting for obstructions and excessive temperature. Allow to cool. Retry. Check and replace spark ignitor or ignitor wire. Verify 120V at blue wire (pin #7). If 120V, then you must also have spark. Replace gas valve. Verify continuity at ECO. Replace gas control. Page 28

30 Unable to light pilot (but I can hear the spark ignitor) You may see one of the following flash codes: 1/1 3/1 3/3 Pilot does not stay lit Main burner will not stay lit 1. Gas supply turned off 2. Gas control valve is damaged. 3. Pilot burner orifice is clogged 4. Pilot tube pinched or clogged 5. Air in gas line 6. Spark gap to large 7. Spark ignitor damaged 1. Venting downdraft (or other improper draft) 2. Clogged flue 3. Pilot partially clogged 4. Improper gas pressure 5. Improper ground 6. Spark ignitor is damaged, dirty or has loose connection 7. Poor flame rectification 1. Low gas pressure 2. Gas valve or control board damaged 3. Main burner orifice or plate clogged 4. Main burner supply tube clogged or pinched 5. Poor flame rectification Turn on gas supply; turn on gas valve. Makes sure the white Molex connector is tight. Verify 120V at blue wire. If 120V the control board is working, but the gas valve is not; replace gas valve. If you do not have 120V then electronic control board is damaged; replace control board. Inspect and clean pilot orifice and pilot burner. Clean, straighten or replace. Purge air from gas line. Cycle unit after lockout and try again. Reset spark gap to 7/64. Check spark ignitor and ignitor wire; replace if damaged. Check for proper draft venting. Check for other drafts that could blow out the pilot light. Inspect and clean flue way. Inspect and clean supply tube, pilot orifice, and pilot burner. Check grounding of pilot burner and main burner. Check, clean, repair or replace spark ignitor. Check that pilot flame covers the pilot hood and is steady and blue. Check gas supply pressure. Verify manifold pressure. Makes sure the white Molex connector is tight. Verify 120V at pin #6. If 120V the control board is working, but the gas valve is not; replace gas valve. If you do not have 120V then electronic control board is damaged; replace electronic control. Clean or replace. Clean, straighten or replace. Check that pilot flame covers the pilot hood and is steady and blue. Page 29

31 Scale on burner and pilot assemblies 1. Condensation 2. Contaminated atmosphere Sooting 1. Combustion air inlets or flue way is restricted 2. Not enough combustion or ventilation air supplied to room 3. Improper gas pressure 4. Burner orifice or plate dirty Yellow flame 1. Scale on top of burner 2. Burner orifice or plate dirty 3. Flue way clogged 4. Improper gas pressure 5. Not enough combustion or ventilation air supplied to room Burner flame noisy 1. Improper gas pressure (whistling) 2. Burner orifice dirty Burner flame too high 1. Improper gas pressure 2. Wrong orifice Water too hot 1. Thermostat setting too high 2. Thermostat out of calibration Slow hot water 1. Burner orifice clogged recovery Noisy water heater (rumbling and sizzling) Excessive relief valve operation Rusty or black water Smelly water (rotten egg odor) 2. Improper gas pressure 1. Scale or sediment build up in bottom of tank 2. Flue baffle loose 3. Condensation on main burner 1. Excessive water pressure 2. Excessive temperature 1. Anode rod dissolved 2. Excessive sediment build-up 3. High manganese content in Bacteria formation inside water tank Excessive condensation caused by undersized heater. Check for contaminant causing chemicals near the heater. Remove obstruction or debris from heater or flue way. Improve combustion air or ventilation air supply. Check and adjust. Inspect and clean. Clean burner plate. Inspect and clean. Inspect and clean. Check and adjust. Improve combustion air or ventilation air supply. Check and adjust. Inspect and clean. Check and adjust. Install correct orifice. Adjust thermostat to lower setting. Check and replace control valve. Check and clean. Check and adjust. Clean tank. Reset and tighten. Inspect for condensation (normal) and tank leaks. Install proper pressure reducing valve on cold side. Check for open or closed system. Install expansion tank. Check thermostat; lower setting or replace gas valve. Check anode rod and replace. Drain tank; replace tank if sediment build up is excessive. Replace anode rod if deteriorated. Add automatic chlorine feeder to cold water inlet side of tank. Milky water Aerated water Allow a glass of hot water to set for a few minutes. If the water turns clear, the condition is a natural occurrence. Table 7 Guardian PowerVent Troubleshooting Table Page 30

32 HOW TO REMOVE THE GUARDIAN POWERVENT INNER ACCESS DOOR 1. Shut off gas supply to water heater. Turn gas valve to OFF. 2. Remove jacket door. 3. Unscrew the pilot supply tube (7/16 ) and the main gas supply tube (3/4 ), and remove the ignitor wire from the gas control valve. 4. Remove the four tamper resistant screws at the corners of the burner. You will need a #20 size TORX head tool. 5. Remove burner access door. Remove the old door gasket. Clean metal surfaces. (Gasket will be replaced during reinstallation of inner door. See gasket shipping package for more replacement instructions.) 6. Reassemble in reverse order. Install new gasket. 7. Turn gas supply back on. Turn gas valve to ON. Turn thermostat up to demand heat. 8. Verify main burner operation. Page 31

33 9. Check main supply tube and pilot supply tube at the gas control valve for gas leaks with a soap and water solution. Bubbles indicate a leak. Tighten all connections if a leak is found. 10. Set temperature not to exceed 120 degrees. Replace jacket door. Page 32

34 HOW TO REMOVE THE GUARDIAN POWERVENT PILOT IGNITER ASSEMBLY 1. Shut off gas supply to water heater. Turn gas valve to OFF. 2. Unscrew the pilot supply tube (7/16 ) and the main gas supply tube (3/4 ), and remove the ignitor wire from the gas control valve. 3. Remove the four tamper resistant screws at the corners of the burner. You will need a #20 size TORX head tool. 4. Remove burner access door. Remove the old door gasket. Clean metal surfaces. (Gasket will be replaced during reinstallation of inner door. See gasket shipping package for more replacement instructions.) 5. Remove the entire pilot igniter assembly by pulling the orange grommet from the inner door. Work from the inside of the door. 6. Then remove the igniter from the mounting bracket with a Phillips screw driver. Page 33

35 7. Install the new pilot igniter assembly by threading the loose ends of the assembly thru the door hole and pushing the orange grommet into the hole from the backside. Reattach the assembly to the mounting bracket with the Phillips screw. 8. Ensure the grommet is fully seated by tugging on it. The smaller rubber flange should penetrate to the front of the door. 9. Reconnect the pilot supply tube (7/16 ) and the main gas supply tube (3/4 ), and attach the orange ignitor wire to the gas control valve. 10. Turn gas supply back on. Turn gas valve to ON. Turn thermostat up to demand heat. Verify main burner is on. 11. Set Thermostat not to exceed 120 degrees. Replace jacket door. Page 34

36 HOW TO REMOVE THE GUARDIAN POWERVENT GAS CONTROL 1. Turn gas valve to OFF. Shut off the gas to the unit. Shut off the water supply to the unit. Remove jacket door. Remove gas line. 2. Connect a garden hose to the drain valve and open the drain valve. Lift the silver lever on the T&P valve to vent the unit and allow the tank to drain thru the drain valve. 3. Unscrew the pilot supply tube (7/16 ) and the main gas supply tube (3/4 ), and remove the ignitor wire from the gas control valve. 4. Disconnect all wiring and Molex connectors from the gas valve. 5. When the water is drained, unscrew the gas valve. It should loosen counter clockwise as you are looking at it. Use a inch threaded black pipe as a cheater bar if needed. 6. Put plenty of pipe dope (or other sealer required by local code) on the threads of the valve. Install gas control. Page 35

37 7. Close drain valve; remove hose and turn water back on. Allow unit to refill. Leave T&P open until water comes out the drain line. Open a hot water faucet and allow it to run for about 30 seconds. This will evacuate all of the air from the tank. Check for water leaks and tighten the gas valve if necessary. 8. Reconnect the pilot supply tube (7/16 ) and the main gas supply tube (3/4 ), and attach the orange ignitor wire to the gas control valve. 9. Reinstall the gas line to the valve. You will need pipe dope suitable for gas supply (or other sealer required by local code) on the black pipe connection to the gas valve. 10. Turn on the manual gas shut-off valve near the water heater. Use a soapy water solution to test for leaks at all connections and fittings to the gas valve. Bubbles indicate a gas leak that must be corrected. 11. Turn gas valve to ON and turn the thermostat up to demand heat. After running main burner for 3 minutes, recheck for gas leaks at the gas valve connections. Don t forget the pilot and main burner supply tube connections at the bottom of the valve. 12. Set red temperature dial on thermostat to a safe position not to exceed 120 degrees. Replace jacket door. Page 36

38 HOW TO REPLACE THE GUARDIAN POWERVENT VENT OVER TEMP SWITCH 1. Turn the unit off and unplug the heater. If not, you could be shocked with 120 volts of electricity. 2. Unscrew the over temp switch on the draft hood. 3. Remove the two 5/16 inch nuts on the control box. 4. Remove the green grounding strap from the blower housing. 5. Turn the control box over and remove the two blue wires from the terminals. 6. Remove the wiring harness from the control box and discard. 7. Thread the blue leads of the new over temp switch wiring harness thru the control box. Page 37

39 8. Connect one lead to the vacuum switch; the other lead to the control panel. 9. Connect the heat sensor to the draft hood. 10. Reconnect green grounding wire. 11. Replace control box on blower motor housing and re-install the nuts. 12. Plug unit back in; turn unit on; and conduct function check. Page 38

40 HOW TO REPLACE THE GUARDIAN POWERVENT VACUUM SWITCH 1. Turn the unit off and unplug the heater. If not, you could be shocked with 120 volts of electricity. 2. Unscrew the vacuum switch on the control housing and remove the tubing. 3. Remove the red wire and blue wire from the vacuum switch. 4. Discard old vacuum switch. 5. Insert the red wire to the NO/NC terminal. 6. Insert the blue wire to the COM terminal. 7. Re-insert the vacuum switch into the control box and replace the screws and tubing. 8. Plug unit back in; turn unit on; and conduct function check. Page 39

41 HOW TO REPLACE THE GUARDIAN POWERVENT ELECTRONIC CONTROL MODULE 1. Turn the unit off and unplug the heater. If not, you could be shocked with 120 volts of electricity. 2. Turn the gas valve to OFF Remove plastic grey cover to the Molex connections 3. Disconnect all wiring and Molex connectors from the gas valve. 4. Using a TORX 15 tamper resistant screwdriver, remove the single screw on the grey control module housing. Keep the screw. 5. Using a flat tip screwdriver, gently pry the retaining tabs holding the control module in place. There are four tabs; One on top; one on bottom; and two on the left side of the valve Page 40

42 6. Remove and discard the old plastic grey module. 7. Place new electronic module in position and press firmly to engage locking tabs. 8. Replace TORX 15 screw. 9. Reconnect Molex connectors in accordance with connection diagrams. 10. Set temperature selector to Vacation. Turn gas valve to ON. Page 41

43 11. Turn water heater on at blower motor. 12. Set thermostat setting not to exceed and check main burner operation. HOW TO REPLACE THE GUARDIAN POWERVENT FLAMMABLE VAPOR (FV) SENSOR 1. Turn the unit off and unplug the heater. If not, you could be shocked with 120 volts of electricity. 2. Turn the gas valve to OFF. Remove plastic grey cover to the Molex connections 3. Remove outer door jacket 4. Remove the white Flammable Vapor (FV) Sensor Molex connector. Page 42

44 5. Unthread wires from retainer clips on main burner supply tube. 6. Gently grab and pull the sensor from the mounting hole. Unthread the remainder of the wiring harness. 7. Replace in reverse order. 8. Rethread wires thru retainer clips on burner supply tube and reconnect Molex connect to control valve. 9. Cycle the PowerVent and inspect for main burner. Set red temperature dial on thermostat to a safe position not to exceed 120 degrees. Page 43

45 RESET PROCEDURES FOR INVENSYS CONTROL 1. Inspect the installation/location for the presence of materials that could produce flammable vapors (ex: gasoline, cleaning compounds, paints/solvents) or the presence of bleach or ammonia. Remove any of these materials and thoroughly ventilate the area where water heater is located. If the area is not clear of flammable vapors, the sensor will re-trip immediately. 2. Interpret flash code (Refer to SVC-900 pages 17 thru 20) a. 2-1: Flammable vapors present b. 2-3: FVD Interface Failure/Miswiring 3. Turn off blower power switch on water heater and unplug power cord. 4. Disconnect flammable vapor sensor wire connector from control valve and measure electrical resistance between connector test points. Figure 14 Invensys Reset Procedure a. Sensor resistance should be above 9k ohms and below 45k ohms. If the sensor is within this range, proceed to Step 5. b. If the sensor resistance is less than 9k ohms or greater than 45k ohms, replace the sensor and sensor wire harness. 5. Re-install the sensor wire connector to the control valve, re-install the wire cover, and follow the reset instructions below: Resetting the control for 2-1 or 2-3 error codes. The following steps must only be performed after completing the above procedure. 1. Place the red temperature setting dial on Vacation. 2. Reapply power to the water heater and wait for 3 seconds for the system self-diagnostic check. 3. Within the first 30 seconds, the temperature dial must be rotated back and forth crossing the 120 degree mark at least six (6) times. (You can do this by rotating the red dial from Vacation to Hot to Vacation ) 4. This will reset the control and display a normal flash code (slow blinking). 5. If (2-1) or (2-3) flash code persists replace the control module and sensor. Page 44

46 WHITE RODGERS GAS VALVE Effective October 2007, we transitioned to the White Rodgers Thermostat Control for our standard Guardian PowerVent residential gas water heaters. This change affected both natural and LP gas models. Below is the troubleshooting step for each potential error code. In the event you display the code for a flammable vapor event, please call the technical support line. Figure 15 White Rodgers Control Gas Valve Error 1 Indications An open earth ground circuit to the water heater. Display Troubleshooting 1. Check that the earth ground conductor is properly connected at the fuse box or breaker panel and the water heater. 2. Check that the grounding conductors on the water heater are properly connected and secure. 3. Check green grounding wire connection on side of control valve. Error 2 Indications The self diagnostic test detected a wiring error or a high resistance to earth ground. Display Troubleshooting 1. Check for proper connection of the line neutral and line hot wires. 2. Check that the appliance is securely connected to earth ground. Error 3 Indications Display The pressure switch remained closed longer than 5 seconds after the call for heat began. This error code will appear within 5 seconds if the pressure switch will not open. Troubleshooting 1. The pressure switch wiring is incorrect. 2. The pressure switch has been jumpered. 3. The pressure switch is defective (contacts inside switch permanently closed) and must be replaced. Page 45

47 Error 4 Indications The pressure switch remained open longer than 5 seconds after the combustion blower energized. Display Troubleshooting 1. The pressure switch wiring is incorrect or disconnected. 2. The pressure switch tubing in not connected correctly or pinched off. 3. Obstructions or restrictions in the water heater exhaust venting. Remove venting and recycle to rule out venting. If unit goes to main burner, the venting is the problem. If the code repeats, replace inducer/pressure switch. Error 5 Indications The self diagnostic test has detected an error in the Hot Surface Ignitor circuit. Display Troubleshooting 1. Check that the wiring harness Molex is connected and secure. 2. Disconnect the ignitor connector and measure the ignitor resistance with an ohmmeter between pins 1 and 2. Resistance should be between 11.5 and 18.8 ohms. 3. If the reading is incorrect, replace the Hot Surface Ignitor. 4. If the above checks are good, replace the INTELLI-VENTTM control. Error 6 Indications Display The maximum number of ignition retries or recycles has been reached and the system is in lockout. (This means there was no flame rectification to the control to verify main burner.) Troubleshooting 1. Check if the gas supply is off or too low to operate. 2. Check the flame sense rod to see that it is located properly and free from contamination. Reposition the flame sense rod or lightly clean with an abrasive cloth. 3. The Hot Surface Ignitor may not be positioned on the burner correctly. Reposition as necessary. 4. Low voltage to the water heater. (Verify the hot surface ignitor glows by recycling power Page 46

48 and looking thru sight glass window. If you have a glowing ignitor, then your problem is probably fuel related.) 5. Thermal Release Device is damage or missing. No oxygen in combustion chamber. 6. Inadequate fresh air to support combustion inside combustion chamber. 7. Main burner supply tube is blocked, bent or restricted; burner orifice is blocked or restricted. Error 7 Indications The self-diagnostic test found a problem with the gas valve driver circuit. Display Troubleshooting 1. Cycle power to the water heater off for 10 seconds and then back on. 2. If the above step did not clear the error, the INTELLI-VENT control must be replaced. Note: There are no further tests to conduct when the control fails one of its self-diagnostic tests. If the valve thinks there is something wrong; then the recourse is to replace the control. Error 8 Indications The self-diagnostic test found a problem with the internal micro computer Display Troubleshooting 1. Cycle power to the water heater off for 10 seconds and then back on. 2. If the above step did not clear the error, the INTELLI-VENT control must be replaced. Note: There are no further tests to conduct when the control fails one of its self-diagnostic tests. If the valve thinks there is something wrong; then the recourse is to replace the control. Error 9 Indications The self-diagnostic test found a problem with the internal circuit Display Troubleshooting 1. Cycle power to the water heater off for 10 seconds and then back on. 2. If the above step did not clear the error, the INTELLI-VENT control must be replaced. Note: There are no further tests to conduct when the control fails one of its self-diagnostic tests. If the valve thinks there is something wrong; then the recourse is to replace the control. Page 47

49 Error 10 Indications Flame signal sensed out of proper sequence. ( The flame probe sensed fire when it was not suppose to.) Display Troubleshooting 1. Cycle power to the water heater off for 10 seconds and then back on. 2. If the above step did not clear the error, the INTELLI-VENT control must be replaced. Error 11 Indications Display High temperature thermal cut-off (ECO) switch is tripped. (This one time use device trips when the water temperature exceeds F.) Troubleshooting 1. Cycle power to the water heater off for 10 seconds and then back on. 2. If the above step did not clear the error, the INTELLI-VENT control must be replaced. Error 12 Indications The self diagnostic test has indicated one of the temperature adjustment buttons is stuck closed. Display Troubleshooting 1. Make sure that there are no objects leaning against the front of the control 2. Lightly press and release each of the buttons once. 3. If the above actions do not clear the error, the control will continue to regulate water temperature at the last setting, but you are not able to change settings unless you replace the INTELLI-VENT control. Error 13 Indications The self-diagnostic test has detected that the water temperature sensor is either open or short circuited. Display Troubleshooting 1. Cycle power to the water heater off for 10 seconds and then back on. 2. If the above step did not clear the error, the INTELLI-VENT control must be replaced. Note: There are no further tests to conduct when the control fails one of its self-diagnostic tests. If the valve thinks there is something wrong; then the recourse is to replace the control. Page 48

50 Error 14 Indications Display The self-diagnostic test found a problem with the Flammable Vapor Sensor. (This is not a flammable vapor event. It may be caused by disconnecting the FV sensor Molex, or the FV sensor itself. This includes both short and open electrical connections.) Troubleshooting 1. Check all FV sensor wiring harness connections; and the connections to the back of the sensor. 2. Cycle power to the water heater off for 10 seconds and then back on. 3. If no wiring problems are found, the Flammable Vapor Sensor must be checked. a. Disconnect the FV sensor Molex and measure the resistance of the sensor between the two black wires 2 and 3. If the resistance is less than 9k OHMS or greater than 45k OHMS, then replace the sensor. b. If the FV sensor is between 9K and 45K and the code will not clear by recycling power, replace the INTELLI-VENT control. Page 49

51 Error 15 Indications The control detected the presence of flammable vapors near the water heater and entered lock out. Display This is a permanent lockout and cannot be cleared by cycling power. Control may be reset. Troubleshooting 1. Disconnect the FV sensor Molex and measure the resistance of the FV sensor between the two black wires 2 and Write down this resistance and call the technical support line at for further instructions. 4. The control is field resettable; however, we probably need to replace the FV sensor first. Page 50

52 Figure 16 White Rodgers Connection Diagram Page 51

53 RESET PROCEDURES FOR WHITE RODGERS CONTROL 1. Inspect the installation/location for the presence of materials that could produce flammable vapors (ex: gasoline, cleaning compounds, paints/solvents) or the presence of bleach or ammonia. Remove any of these materials and thoroughly ventilate the area where water heater is located. 2. Interpret error code. The White Rodgers control is able to tell the difference between a disconnected sensor and a Flammable Vapor incident. The only time you need to apply the reset procedure is with Error Turn off blower power switch on water heater and unplug power cord. 4. Disconnect flammable vapor sensor wire connector from control valve and measure electrical resistance between connector test points #2 and #3 (black wires). 5. Sensor resistance should be above 9k ohms and below 45k ohms. If the sensor is within this range, proceed to Step If the sensor resistance is less than 9k ohms or greater than 45k ohms, replace the sensor assembly. Call technical service for the sensor kit. 7. Re-install the sensor wire Molex connector to the control valve and follow the reset instructions on the next page. Page 52

54 The following steps may only be performed after completing the FV Sensor check procedure. 1. Reconnect power to the water heater and turn the unit on. The FV error code will reappear. Within 30 seconds 2. Press and hold left and right arrow keys on the control valve, at the same time, until the green light begins to blink. (If the green light does not blink, then you did not press the buttons at the same time.) While the green light is blinking, let go of the buttons and 3. Press left and right temp adjustment keys in the following sequence: Left Right Left, Left Right Left Right, Right 4. If the error code is reset, all the lights will come on. The valve is now reset. Page 53

55 Rheem Water Heaters Ruud Water Heaters 2600 Gunter Park Drive East Montgomery, AL HEATER3 WATER HEATERS PRINTED IN U.S.A. 01/08 FORM NO. SVC900; Rev 1