Service & Trouble Shooting Manual Condensing Dual Purpose Water Heater (REV. 241013-03)
TABLE OF CONTENTS 1. Installation (authorized personnel only) 3 Installation Of The Dual Purpose Water Heater (DPWH) 3 Water Connections 3-4 Gas Connection 4 Electrical Connections 4 2. Commissioning The Appliance 5 General Warnings 5 Filling The System 6 Filling The Condensate Trap 7 Ignition Of The DPWH 7 Heating Mode 8 Domestic Mode 9 3. Maintenance (Authorized Personnel Only) 10 General Warnings 10 Dual Purpose Water Heater (DPWH) Inspection 10 Draining The Central Heating And Domestic Hot Water System 11 4. Troubleshooting Error Codes Diagnostics 12 E01 Ionization / Flame Sensor Lock-Out 13-16 E02 Safety Thermostat Tripped / Air Pressure Switch Tripped 17-18 E03 Flue Gas Thermostat (Thermofuse) Tripped 19-20 H2O Low Water Pressure Alarm 21-22 E05 Heating Sensor Malfunction 23-24 E06 D.H.W Sensor Malfunction 25-26 E12 D.H.W Storage cylinder Sensor Malfunction 27-28 E16 Induced Draft Electric Fan Malfunction 29-30 E22 Parameter Programming Request 31-32 E35 Flame Sensor Malfunction 33-34 E42 Fan Printed Circuit Board Malfunction 35-36 5. Exploded Parts View Flowmax 90 Hydraulic System 37 Flowmax 90 Thermal System 38 Flowmax 120 Hydraulic System 39 Flowmax 120 Thermal System 40 Flowmax 170 Hydraulic & Thermal System 41 6. Function Codes 42 07- Flue Test Function Active (Chimney-Sweeper) 42 08 - Frost Protection Central heating circuit 42 09 - Frost Protection Domestic Hot Water (D.W.H.) circuit 42 13 - Frost Protection Domestic Hot Water (D.W.H.) circuit for storage DPWH 42 28 - Legionella Prevention Function 42 31 - Incompatible Remote Control 42-2 -
1. Installation (authorized personnel only) 1.1 Installing the Dual Purpose Water Heater (DPWH) The cardboard material used for packaging the appliance is fully recyclable. It is recommended that the packaging material is only removed prior to installing the DPWH. The manufacturer will not be held responsible for damage caused by incorrect storage of the product. 1.2 Water Connections In order to safeguard the primary heat exchanger and circulation pump, especially in case of DPWH replacement, it is recommended that the system is hot-flushed to remove any impurities (oil and grease) from the pipes and radiators. If this DPWH is installed in an application where the supply water is hard, it must be treated with either a water softener and or a filtration system which removes hardness within the water or by using sequestering agents that reduce the amount of scale deposits. Damage to the DPWH as a result of water in excess of 14.5 gpg (250mg/L) of hardness is not covered by FLOWMAX Limited warranty. If there a problem with the water quality, contact your local water conditioning company for equipment to condition the water supply to this appliance. The cold water supply pressure at the inlet to the DPWH must be between 7.25 psi (0.5 bar) and 87 psi (6 bar). In areas with higher water inlet pressure a pressure reducing valve must be installed before the DPWH. The frequency of the primary heat exchanger coil cleaning depends on the hardness of the main water supply and the presence of residual solids or impurities, which are often present in the case of new installations. If the characteristics of the main water supply are such that require it to be treated, an appropriate treatment device should be installed. While in the case of residues, an in-line filter should be sufficient. Central Heating Circuit In order to prevent scaling or deposits from forming in the primary heat exchanger, the main supply water to the heating circuit must be treated according to the requirements of local standards. This treatment is indispensable in cases where the system is frequently topped-up or when the system is often either partially or fully drained. Condensate Drain FLOWMAX DPWH is a high efficient gas appliance that creates condensation when operating. A condensate trap and flexible drain pipe comes factory installed inside each unit. The condensate trap must be primed before operation to prevent exhaust gases from entering the building. Follow your local code with regards to the disposal of condensation Here are several options for disposal of condensate o o o o From combination DPWH direct to drain From combination DPWH to neutralizer to drain From combination DPWH to laundry tub (bottom of DPWH must be above the height of the laundry tub & must have a negative slope to properly drain) From combination DPWH to condensate pump to laundry tub (for long distances between DPWH and laundry tub or when bottom of the DPWH is installed below height of the laundry tub) Failure to install the condensate discharge properly will affect the reliability of the DPWH. All units installed with vertical exhaust must have an additional approved condensate drain. Fittings must be ULC S636 approved. Failure to properly connect the condensate line will cause combustion gases to enter the room, possibly causing serious injury to occupants or death. - 3 -
Note: Check with your municipality, local codes, or local gas company to determine if disposal of combustion condensate is permitted. In the State of Massachusetts the condensate must be neutralized prior to entering a drain. Use only PVC, vinyl or CPVC pipe for the condensate drain line, metal pipe work is not suitable for condensate discharge system. The condensate drain line should be a minimum of ½ diameter. It connects to the existing corrugated hose and must be supported to prevent sagging. The manufacturer supplies a barbed ¾ to ½ reducer for this connection. Keep the length of the condensate drain as short as possible. Long runs or applications where the nearest drain is above the DPWH will require the use of a condensate pump. Size the pump to allow for a maximum condensate discharge of 2 gpm from the DPWH. The end drain pipe must not be submerged in water or blocked in any way. Condensate will begin flowing out of the DPWH within 15 minutes after operation has started. Be certain to check that condensate is freely flowing from the drain piping after the system has been installed. Do not run the condensate line outside. Take measures to prevent the condensate drain lines from freezing (insulation, heat tape, electric heaters, etc.) if in unconditioned space. Be sure to clean the condensate trap at least once per year to prevent any problems. Be sure to check and clean the condensate trap to prevent blockage. After cleaning, be sure to check for any leaks of condensed water or flue gas. 1.3 Gas Connection Check the internal and external seals of the gas supply system. A gas cock must be installed upstream of the appliance Before starting the appliance, ensure the type of gas corresponds to that for which the appliance has been setup. The gas supply pressure must be between the values reported on the rating plate. Conversion of the appliance from Natural Gas to LPG or vice versa must be carried out by qualified personnel. 1.4 Electrical Connections DO T connect 220-240VAC and any other voltage to this FLOWMAX Combination DPWH. This will damage the DPWH and void the warranty. The electrical supply required by the DPWH is 120VAC at 60Hz with proper grounding. If the main power supply wire leads are damaged in any way, switch off the appliance and have the wire leads replaced by a qualified electrician. - 4 -
2. Commissioning the Appliance 2.1 General Warnings The following operations must be carried out by professionally qualified personnel, registered in accordance with current legislation. The DPWH leaves the factory pre-set and tested for burning Natural Gas. Nevertheless, when starting the DPWH for the first time, make sure that the information on the rating plate corresponds to the type of gas being supplied to the DPWH. Once the system has been filled and the necessary adjustments made, remember to tighten the screws of the gas valve test port. Ensure there are no gas leaks from the tests port and from any pipe fittings upstream of the gas valve. Ensure there are no gas leaks from the test port and from any pipe and or fittings. Preliminary Operations Switching the DPWH on for the first time means checking that the installation, regulation and operation of the appliance are correct: Check that the rating on the rating plate corresponds to that of the main electrical supply networks (gas, electricity, water). Check that the power supply voltage to the DPWH complies with the rating plate (120V 60Hz) and that the live, neutral and ground wires are properly connected. Check that the gas supply is correctly sized for the flow rate required by the DPWH and that it is fitted with all the safety and control devices stipulated by current regulations. Check that the supply of combustion air and exhaust and condensate discharge systems are functioning correctly and are in line with current codes and standards. Check that the exhaust vent and its connections to the termination comply with the requirements of current codes and standards for the type of appliances installed. Check that the service valves are open. Check that the condensate drain system including outside the DPWH (exhaust system condensate collection devices), allows the condensate to flow freely to the drain. Check that there are no flammable materials or liquids in the immediate vicinity of the DPWH. Flush out both primary and domestic hot water circuits (see 4.3 Flushing the system ). - 5 -
2.2 Filling the System Check the properties of the water supply and install the appropriate treatment devices if the main water supply has a hardness rating more than 14.5 gpm (250 mg/l) in order to prevent scaling and eventual damage to the D.H.W primary heat exchanger. Use only clean tap water to fill the system. AIR VENT VALVE AIT AIR VENT VALVE PLUG AIR PUMP VENT VALV PLUG PUMP PUMP PUMP PLUG PLUG A pre-filtering system can be installed on the incoming water supply to help reduce impurities and limestone. This DPWH must have adequate water flowing through it whenever the burner is on. Failure to do this will damage the unit and void the warranty. Once the water pipes have been connected, close the gas cock and fill the system as follows: Check that the plug on the air vent valve attached to the circulating pump has been opened to allow air to escape from the system (Diag. 1). Open the main domestic water supply valve Open the manual filling tap R by turning counter-clockwise (Diag. 2) until pressure is in proper range and H20 is off display, CAUTION over pressurizing will cause the relief valve to open. Unscrew the brass plug on the circulating pump to remove any trapped air, check that the pump is rotating freely. Rotate the impeller with a screwdriver, then replace and retighten the brass plug when water starts to flow (Diag. 1). It may be necessary to use a cordless drill at times in order to ensure that the impeller rotates freely. 1 Diag. 1 1 2 Diag. 2 2 R M R M Before switching on the DPWH, purge air completely from the air vent valve positioned on the top of the exchanger (Diag. 3) Open the air vents on the radiators and monitor the air evacuation process. When water starts to flow out of the radiators, close the air vents Use the pressure gauge M (Diag. 2) to check that the system s pressure reaches the middle of the green area (equal to 17.4 PSI, Diag. 4). On completion, make sure that the filling tap R is closed If an auto feed is not present in the system, check the water pressure in the system. If the pressure has fallen, re-open the manual filling tap counter-clockwise until the H2O code disappears from the display. The ideal pressure should be the middle of the green area (1, 2 bar / 17.4 p.s.i.). Upon completion, close the manual filling tap (clockwise). 3 Diag. 3 21.7 PSI DiaFig 17.4 PSI. 2 7.2 PSI GREEN AREA 43.5 PSI - 6-4 Diag. 4
2.3 Filling the Condensate Trap The condensation trap must be filled with water prior to starting the DPWH. This process prevents flue gases from flowing back through the trap. The filling operation is carried out as follows (Diag. 5): Remove plug T and fill the trap S three quarters full with water Replace plug T and connect the drainpipe P into a condensate discharge trap conforming to current legislation Attention! It is recommended to clean the condensate trap after a few months operation in order to remove any deposits/residuals left after the first condensate passage within the DPWH. Residuals may interfere with the proper operation of the trap itself. 2.4 Ignition of the DPWH 1 Diag. 5 T S Once the system has been filled, proceed as follows: Check that the exhaust vent is free of obstructions and correctly connected to the DPWH Plug the DPWH into a 120V outlet Open the gas cock Press the ON/OFF switch and leave in the ON position, after a few seconds the circulating pump will start to run Press the top right button on the control display in order to setup the DOMESTIC MODE or HEATING MODE OR DOMESTIC/HEATING mode. The icons will appear and the display will light up (fixed light) to indicate that the DPWH is working On a call for heating or domestic the appropriate icon will flash, and the automatic ignition system will then light the burner. This operation is repeated 3 times. It may however be necessary to repeat the operation in order to eliminate air from the gas line. To repeat the operation, wait approximately three minutes before re-attempting to light the DPWH. To reset the DPWH press the main ON/OFF switch off and on again and repeat the lighting procedure. With the DPWH ignited, the system may still emit noises from the primary heat exchanger. This operation must be repeated until all the air has been removed and replaced with water. Ensure the pump is running whenever the DPWH is operating. If an auto feed is not present in the system, check the water pressure in the system. If the pressure has fallen, re-open the manual filling tap counter-clockwise until the H2O code disappears from the display. The ideal pressure should be the middle of the green area (1, 2 bar / 17.4 p.s.i.).upon completion, close the manual filling tap (clockwise). If the CO2 value at high fire does not correspond to the specified value shown in the installation manual, adjust screw V (Diag. 6) on the venturi clockwise to reduce the CO2 value or counter-clockwise to increase It. Make certain the unit is operating on high fire. fig.1 Diag. 6 V - 7 -
2.5 HEATING MODE Call For HEATING: Circulation pump is energized. The combustion fan blower purges the combustion chamber, then ramps to ignition speed (HZ) The ignition transformer provides a spark, gas valve opens, 3-way valve moves from domestic park location Ignition transformer drops out after flame is sensed (1.2 sec), gas valve remains open Combustion blower speed modulates (HZ) to meet the desired loop temperature. Venturi maintains combustion throughout range Limits and sensor are constantly monitored by the main control board. Sensors cause the unit to modulate to meet load. Tripping of any limit will cause the unit to shut down and display an error code Upon satisfying call, burner shuts down, unit post-purges, pump continues to operate for 180 seconds - 8 -
2.6 DOMESTIC MODE Request for the D.H.W. production: The flow switch closes Circulation pump is energized. The combustion fan blower purges the combustion chamber, then ramps to ignition speed (HZ) The ignition transformer provides a spark, gas valve opens, 3-way valve remains in domestic park position Ignition transformer drops out after flame is sensed (1.2 sec), gas valve remains open Combustion blower speed modulates (HZ) to meet the desired loop temperature. Venturi maintains combustion throughout range Limits and sensor are constantly monitored by the main control board. Sensors cause the unit to modulate to meet load. Tripping of any limit will cause the unit to shut down and display an error code Upon satisfying call, burner shuts down, unit post-purges, pump continues to operate for 90 seconds - 9 -
3. Maintenance (authorized personnel only) 3.1 General Warnings All maintenance operations must be carried out by professionally qualified personnel authorized by FLOWMAX. The frequency of DPWH maintenance is recommended to be carried out once a year. In order to guarantee the long life of the appliance and in accordance with the current gas safety regulations, only use original parts Before carrying out any type of maintenance operation, disconnect the appliance from the electrical supply and shut-off the gas supply. Warranty will not be honoured if recommended maintenance is not followed. 3.2 Dual Purpose Water Heater inspection In order to ensure that the DPWH operates efficiently and safely, it is recommended that the appliance be inspected by a professionally qualified technician at least once a year. The following operations should be carried out annually: Check that the condition of the gas seals and replace where necessary. Check that the condition of the water seals and replace where necessary. Visually inspect the condition of the combustion chamber and flame. Check that the combustion is correctly regulated, if necessary proceed to the section Commissioning the DPWH. Remove and clean any oxidation from the burner. Refer to section 6.7 in the installation manual. Check that the integrity and positioning of the washer on the cover of the burner. Refer to section 6.7 in the installation manual. Check that the primary heat exchanger and clean if necessary. Refer to section 6.7 in the installation manual. Check that the maximum and minimum modulation pressures and the modulation itself. Check the condition and operation of the ignition and gas safety systems. If necessary, remove and clean the scaling from the ignition and flame sensor electrodes. Pay particular attention when replacing them as they are at the correct gap from the burner. Refer to section 6.7 in the installation manual. Check that the heating safety systems: temperature limit safety thermostat, pressure limit safety device. Check that the pre-fill pressure of the expansion tank (see expansion tank rating plate). For safety reasons, periodically check the integrity and operation of the exhaust system. Check the connection to the main electrical supply and that it complies with what is stated in the DPWH s instruction manual. Check the electrical connections inside the control panel. Check the D.H.W flow rate and temperature. Check that the condensate drain system is working correctly, including any parts of the system outside the DPWH such as condensate collection devices along the length of the exhaust vent and/or any acid neutralising devices. Check that the condensate flows freely and that there are no exhaust fumes present within the appliance. Warranty will not be honoured if recommended maintenance is not followed. - 10 -
3.3 Draining the central heating system If the need arises to drain the system, this can be done as follows: Switch the system to HEATING mode and trigger a call for heat Once in heating mode unplug the power supply to the DPWH. Wait for the DPWH to cool down. Connect a hose to the system drain port located below the circulating pump and drain to a suitable drainage system. (Diag. 7). Open the system drain valve. Open the air vents on the radiators, starting with the highest and moving down the system to the lowest. When the system has been drained, close the radiator air vents and the drain valve. If only the DPWH needs to be drained, close the supply/return isolating valves on the heating circuit and open the drain valve located at the bottom of the DPWH on the pump manifold (Diag. 7). Diag. 7 fig.1 Draining the Domestic Hot Water System If there is a danger of freezing, the domestic hot water system should be drained. This can be done as follows: Close the main water supply valve. Open all the hot and cold water taps. On completion, close all the previously opened taps. - 11 -
4. Troubleshooting The self-diagnostics programmed within the main control board enables the unit to display an error code (8) (Diag. 8) that flashes when a problem arises with any number of components of the appliance. Some codes, namely the errors E01, E02, can be reset by pressing the ON/OFF switch/reset (1). Diag. 8 All the other codes cannot be reset as mentioned above. Only the intervention of a professionally qualified technician might lead to the solution of the problem. Error codes: E01 E02 E03 H2O E05 E06 E12 E16 E22 E35 E42 Ionization Electrode / Flame Sensor Lock Out, No Flame Detected Safety Thermostat Tripped / Air Pressure Switch Tripped Flue Gas Thermostat / Thermofuse Tripped Low Water Pressure Alarm Heating Sensor Malfunction Domestic Hot Water Sensor Malfunction Domestic Hot Water Storage Cylinder Sensor Malfunction Induced Draft Electric Fan Malfunction Parameter Programming Request Flame Sensor Malfunction Fan Control Board Malfunction - 12 -
E01 IONIZATION ELECTRODE / FLAME SENSOR LOCK-OUT E01 IONIZATION ELECTRODE / FLAME SENSOR LOCK-OUT, FLAME DETECTED ENSURE THE GAS SUPPLY VALVE IS ON, CONFIRM GAS PRESSURE AT VALVE INLET 7-10 wc (17mbar- 25mbar) NG IS THE BURNER ON? CHECK FOR CORRECT POLARITY AT THE ELECTRICAL OUTLET IS THERE GAS PRESSURE CHECK THE GAS METER CORRECT POLARITY IS POLARITY CORRECT CHECK THE IGNITION TRANSFORMER FOR OPERATION 120v CHECK THE FLAME SENSOR 2.1-3.5 μa (microamps). IS THE IGNITION TRANSFORMER FUNCTIONING CORRECTLY? REPLACE IGNITION TRANSFORMER REPLACE THE FLAME SENSOR IS THE FLAME SENSOR DAMAGED OR BROKEN CHECK THE SPARK IGNITOR FOR FUNCTION CHECK THE FLAME SENSOR CABLE REPLACE IGNITOR IS THE IGNITOR FUNCTIONING? CHECK THAT THE GAS VALVE IS OPERATING PROPERLY. IF VALVE IS T OPERATING PROPERLY - REPLACE VALVE REPLACE FLAME SENSOR IS SENSOR CABLE BROKEN REPLACE CABLE - 13 -
With no ignition of the main burner, these might be the most likely causes: 1) THE INLET PRESSURE TO THE GAS VALVE MIGHT BE TOO LOW (OR TOO HIGH IN CASE OF LPG UNITS) Test and remedy: Verify the presence of gas from the main gas supply. F Procedure: a) Connect the tube from the manometer onto the pressure test Fig. 1 port on the inlet side of gas valve (inlet pressure test port) (Fig. 1) b) With the main gas cock open, verify if there is enough gas pressure. a. If the natrual gas pressure is not between 7-10 wc (17 mbar 25 mbar) for nat. gas, the gas valve will not operate properly. If this is the case, check the gas meter. b. If the liquid propane gas pressure is not between 10 13.5 wc (25-34 mbar), check the propane gas regulator. Make certian the pressure does not exceed 13.5 wc (34 mbar). If this is the case, check the outlet pressure regulator of the LP tank. 2) DEFECTIVE GAS VALVE Test and remedy: Verify whether the gas valve is operating properly. Procedure: a) Connect the manometer tube onto the pressure test port of the inlet gas valve (low pressure test port). b) With the appliance in the off position, verify the gas pressure displayed on the manometer is between a range of 7-10 w.c. (17 mbar 25 mbar). a. Create a call for heat. b. Using a multimeter, verify 120v is present at the gas valve between the black & orange terminals. If 120v is present and the valve does not open the valve is defective, replace the gas valve. If 120v is not present check the cable that leads back to the main control board for continuity and replace if broken c. If the gas pressure is within range, create a call for heat. As the DPWH goes through it s ignition sequence, verify that the gas pressure changes. If the gas pressure does not drop, the gas valve is defective. At this stage, disconnect the voltage, close the gas cock and replace the gas valve. d. If the gas pressure drops, showing the gas valve has opened, proceed to the next step. 3) IGNITION TRANSFORMER DEFECTIVE OR T WORKING PROPERLY Test and remedy: Verify whether the ignition transformer is operating properly. Procedure: a) Listen for sparking of the electrode or view the spark through the view port on the vestibule of the primary heat exchanger if no sparking heard or viewed see below b) Close the gas cock. Using a multimeter, verify that 120v travels to the ignition transformer (Fig. 2) through the wire leads (Fig. 3) from terminal strip M5 on the main control board, between contacts 1 & 2 (Green & Black Wires). This voltage may be unstable at times. Fig. 2 Fig. 3 Fig. 4 a. If 120v is present, (Fig. 4) visually check that the ignition transformer does not arc to the metal plate it is mounted to. If this is the case, disconnect the voltage and replace the ignition transformer. If the ignition transformer does not arc onto the metal plate and cannot be heard after 3 attempts, the display will show a E01 error code. Disconnect the voltage and replace the ignition transformer. - 14 -
c) If voltage is not present at the ignition transformer, using a multimeter, verify that the terminal strip M5 on the main control board has high voltage between contacts 1 & 2 (Green & Black Wires) on call for heat. a. If 120v is present, disconnect the voltage and check the wire leads for continuity between the control board and the ignition transformer using a multimeter. b. If voltage is not present, disconnect unit power and replace the control board. 4) IGNITION ELECTRODE DEFECTIVE OR T WORKING PROPERLY Test and remedy: Verify whether the ignition electrode is operating properly Procedure: a) Unplug the power supply to the DPWH. b) Close the gas cock. c) Remove the ignition electrode using a Torx 20 screwdriver and make sure its ceramic parts are intact. In case it is damaged or broken, replace it. (Replace the gaskets if they are damaged). d) If the ignition electrode is not broken, verify the gap between the terminals of the ignition electrode is 3 ± 0.5mm. If this is not the case, adjust them to the correct gap and refit the ignition electrode onto the burner. (Diag. 9) (Replace the gaskets if they are damaged). Diag. 9 e) Check by means of a caliper, if there is the correct gap between the terminals of the ignition electrode and the main burner 8 ± 1mm. If it is not the case, adjust to the required gap. Refit to the burner. Should the ignitor be damaged, replace it with a new ignitor. 3.5 -+0.5 If, after all these operations, and the appliance does not light, verify if the ignition electrode arcs. 7 + - 1 7.5 + - 1 Procedure: a) Close the gas cock. b) Unplug the power supply to the DPWH. c) Remove the ignition electrode from the burner and leave it suspended in mid air while it is still connected to the ignition transformer. Make certain the electrode is properly grounded and does not make contact with any metallic surface. (Fig. 5) d) Plug in the power supply to the DPWH. e) Create a call for heat. The appliance will try to ignite. Replace the electrode if it does not create the required spark. (Replace the gaskets if they are damaged). (Extreme caution must be taken when holding the ignition electrode by the silicone tube due to the high current flowing through it when power is applied. ) Fig. 5 5) INSUFFICIENT COMBUSTION AIR Test and remedy: Verify the Combustion Air Supply is not plugged Procedure: a) Create a call for heat. If the appliance ignites with the door open or in the case of the Flowmax 170 series, the combustion air connection opened. Make certain that the combustion air pipe is not obstructed. - 15 -
If the burner actually ignites these might be the likely causes: 1) IONISATION ELECTRODE / FLAME SENSOR DEFECTIVE OR T WORKING CORRECTLY Test and remedy : Verify the ionisation electrode operates properly. Procedure: (see side figures) a) Disconnect the voltage from the main electrical supply. b) Close the gas cock. c) Remove the electrode using a Torx 20 screwdriver and verify it is intact. In case it is damaged or broken, replace it. (Replace the gaskets if they are damaged). d) If the ionisation electrode / flame sensor wire lead is not broken, by means of a caliper, check the ionisation electrode / flame sensor bears the right gap from the burner, i.e. 9 ± 1mm. If this is not the case, adjust the gap or replace the ionisation electrode / flame sensor. 2) WIRE LEADS OF THE IONISATION ELECTRODE / FLAME SENSOR DEFECTIVE OR DISCONNECTED Test and remedy: Verify the integrity of the wire leads. Procedure: a) Disconnect the voltage from the main electrical supply. b) Close the gas cock. c) Check visually the integrity of the wire leads and, if it is damaged or broken, replace it. (Replace the gaskets if they are damaged). d) If it is disconnected, connect the relevant wire leads. f) Plug in the power supply to the DPWH. g) Open the gas cock h) Create a call for heat. The appliance will try e) to ignite. f) Using a multimeter, verify the microamp reading (μa) for the ionisation electrode / flame sensor. In order to measure correctly, you must set your multimeter to read microamps and place your test leads in series with the ionisation electrode / flame sensor and the TF2 tab on electrode the main control board. Create a call for heat. The minumin reading should be between 2.1-3.5 μa (microamps). 3) VENTURI T PROPERLY ADJUSTED Test and remedy: Verify the position of the venturi. Procedure: a) Create a call for heat. The appliance will ignite. Make certain the DPWH is operating on full fire. By means of a combustion analyzer, verify and adjust the CO2 reading according to the installation instructions. Refer to section 5.3 in the installation instructions. b) In order to adjust or tune the venturi, you must first locate the venturi (V) (Diag. 10) which is secured to the combustion blower. By means of a flat heat screwdriver turn the set screw located on the venturi clockwise or counter-clock quarter turn or until you find the correct CO2 reading, as stated in the installation manual. (Please note: All Flowmax models have different CO2 readings). Burner Diag. 10 Primary Heat Exchanger Heat Exchanger Premix Burner Unit B A Ionization Ionization Electrode / Flame Electrode/ Sensor Flame sensor Ignition Electrode - 16 -
E02 SAFETY THERMOSTAT / AIR PRESSURE SWITCH TRIPPED E02 SAFETY THERMOSTAT 203 F (95 C) or AIR PRESSURE SWITCH TRIPPED (requires manual re-set of unit) SAFETY THERMOSTAT 203 F (95 C) AIR PRESSURE SWITCH CHECK THE SAFETY THERMOSTAT FOR CONTINUITY CHECK THE CONTACT BETWEEN TERMINALS 1 & 2 REPLACE THE SAFETY THERMOSTAT IS THERE CONTINUITY? CHECK THE FUSE & AIR INTAKE FOR BLOCKAGE IS THE CONTACT CLOSED CHECK AIR PRESSURE TUBE FOR MOISTURE CHECK FOR CORRECT WATER CIRCULATION IN SYSTEM CHECK FOR CORRECT SAFETY THERMOSTAT FUNCTIONING PROPERLY REPLACE THE PUMP IS THE PUMP WORKING? CHECK THE 3-WAY VALVE FOR CORRECT OPERATION REPLACE THE FLOW THROUGH HEAT EXCHANGER PART REPLACE THE 3-WAY VALVE IS 3-WAY VALVE MOVING? CHECK THE PLATE HEAT EXCHANGER IS THERE SUFFICIENT FLOW THROUGH THE HEAT EXCHANGER CHECK & CLEAN THE MAIN HEAT EXCHANGER - 17 -
7 6 5 4 3 2 1 The likely causes are the following: 1) WATER CIRCULATION Test and remedy: Verify the circulating pump is operating correctly. Upon a demand for heating or domestic, the pump must operate immediately and stay on as long as the demand is present. If the pump does not operate, remove the brass screw at the center of the pump with a flat type screwdriver and spin the impeller by inserting the screwdriver into the opening. This action will cause the pump to rotate. If this action does not allow the pump to rotate with 120v present, replace the pump. If the pump still does not operate, verify that there is 120v present at the pump by means of a multimeter. If 120v is present at the pump, replace the circulating pump. If there is no 120v coming from the main control board, replace the main control board. 2) THE SAFETY THERMOSTAT IS DEFECTIVE Test and remedy: Verify the continuity of the thermostat by testing with a multimeter. In case of no continuity the safety thermostat is open, replace the thermostat. (Fig. 6) Fig. 6 3) THE SAFETY THERMOSTAT WIRE LEADS ARE DISCONNECTED Test and remedy: Verify visually and test with a multimeter if the electrical wiring is intact. Connect the wire leads to the safety thermostat. (Diag. 10) 4) THE DOMESTIC WATER FLOW SWITCH IS T WORKING CORRECTLY Test and remedy: Verify the burner switches off when there is no domestic demand. If that s not the case, remove the micro switch from the domestic water flow switch (Fig. 7) housing and verify the burner switches off. If the burner shuts off, replace the micro flow switch. If the appliance operates when the micro flow switch is not secured in place, replace the main control board. M1 Diag. Fig.3 10 light-blue brown PA TS 5) AIR INLET OR VENT PIPES OBSTRUCTED Test and remedy: Verify the status of the vent pipe. If it is obstructed with foreign objects or water, remove the obstruction before starting the unit. 6) THE AIR PRESSURE SWITCH IS DEFECTIVE OR T WORKING PROPERLY Fig. 7 Test and remedy: Verify if the air pressure switch is operating properly. Procedure: a) Using a multimeter, verify that the contact between 1 & 2 on the air pressure switch is closed (Diag. 11). If the contact is closed and the appliance still displays E02, check the safety thermostat (See point 2 above). If the contact is open, test with a multimeter terminals 1 & 2 on the pressure switch which are normally closed. If the pressure switch is open inspect and clear the exhaust vent pipe and pressure switch tube, if obstructed. If no obstructions are apparent, Use a manometer to check the vent pressure sensed @ high fire. The maximum pressure allowed must be less than the value Diag. shown on the switch with the door closed. In both cases, if the Fig.4 11 error still exisits, disconnect the voltage and replace the air pressure switch. The maximum pressure sensed before the pressure switch opens is 2.14 mbar /.86 w.c. or 3.28 mbar / 1.32 w.c 1 2-18 -
E03 Flue Gas Thermofuse Tripped E03 215 F (102 C) THERMOFUSE FAILURE (N-RESETTABLE) 1 TIME ONLY REQUIRES PART REPLACEMENT CHECK FOR CONTINUITY AT THE THERMOFUSE HIGH FLUE TEMPERATURE (THE FLUE TEMPERATURE HAS EXCEEDED 205 F / 102 C). INSPECT AND CLEAN (IF REQUIRED) THE HEAT EXCHANGER COIL BEFORE REPLACING THE THERMOFUSE IS THERE CONTINUITY? CHECK THE CABLE FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CIRCUIT BOARD - 19 -
brown light-blue The likely causes are the following: 1) THERMAL EXHAUST FUSE DEFECTIVE Test and remedy: Verify the continuity of the thermal exhaust fuse Using a multimeter, check for continuity between the terminals on the thermal exhaust fuse. If there is no continuity, the flue gases have exceeded the temperature of 215 F 102 C and the primary heat exchanger is dirty and or obstructed. Make certain the cirulating pump is operating (See section no water circulation). If that is the case, clean the primary heat exchanger. Procedure: Fig. 8 a) Disconnect the voltage. b) Disconnect the wire leads on the thermal exhaust flue and apply a temporary bridge across the wires (Fig. 8 & Diag. 12). c) Apply voltage to the appliance. d) Make certain the cirulating pump is operating. (See section no water circulation) e) If error EO3 disappears and the burner ignites, clean the primary heat exchanger and replace the thermal exhaust fuse. f) If error E03 is still present, (Flowmax90 & 120 only) the thermal primary heat exchanger link may be open. See section 2 below. Procedure: a. Disconnect the voltage. b. Dis-assemble and clean the burner and primary heat exchanger as per the instructions outlined in the technical manual. Refer to section 6.7 Maintenance Operations Fig. 9 2) THERMAL PRIMARY HEAT EXCHANGER LINK (Flowmax90 & 120 Only) Test and remedy: Verify the continuity of the thermal primary heat exchanger link Using a multimeter, check for continuity between the terminals on the thermal primary heat exchanger link located on top of the primary heat exchanger. (Fig. 9). If there is no continuity, the flue gases have exceeded the temperature of 102 C / 215 F and the primary heat exchanger has been compromised. If this is the case, replace the primary heat exchanger. Refer to section 6.7 Maintenance Operations 3) ELECTRICAL CONNECTION DISCONNECTED Test and remedy: Check the electrical circuit visually for breaks or damage and test with a multimeter to verify continuity. Replace the wire leads, if damaged. TF TF max Fig.1 12 M1 7 6 5 4 3 2 1-20 -
H20 Low Water Pressure Alarm H20 H20 Low Water Pressure Alarm WATER IN THE SYSTEM, INDICATES A LOW WATER SITUATION, UNIT IS OFF UNTIL RESOLVED CHECK THE WATER PRESSURE ON THE WATER PRESSURE GUAGE FILL THE SYSTEM USING THE MANUAL FILL VALVE OR AUTO FILL VALVE (IF USED) IS THERE SUFFICIENT WATER PRESSURE CHECK THE WATER PRESSURE GAUGE CALIBRATION REPLACE THE PRESSURE SWITCH IS THE WATER PRESSURE GAUGE CALIBRATED CHECK THE CABLE FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CONTROL BOARD - 21 -
8 7 6 5 4 3 2 1 The likely causes are the following: 1) INSUFFICIENT PRESSURE Test and remedy: Verify the pressure on the water pressure gauge. The pressure must be within the green area as displayed on the water pressure gauge, i.e. between 7.3 and 17.4 PSI (Diag. 13) or in the middle of the green area, when H2O is no longer displayed on LCD. If the pressure is insufficient, fill the system through the filling loop (Diag. 14) up to approximately 17.4 PSI, until H2O is no longer displayed on the LCD. 21.7 PSI 17.4 PSI 7.2 PSI GREEN AREA 43.5 PSI AIR VENT VALVE AIR VENT VALVE PLUG PUMP If the needle on the pressure guage is within the correct zone of the green area,and H2O is still displayed on the LCD, please check the following points. CAUTION over pressurising will cause the relief valve to open 1 Diag. 13 1 PUMP PLUG 2) DEFECTIVE WATER PRESSURE SWITCH Test and remedy: Verify the water pressure switch is operating properly. Procedure: a) Disconnect the voltage. b) Disconnect the wire leads to the water pressure switch P (Diag. 14 & Fig. 10) c) Apply a temporary bridge between the two terminals of the wire leads (Diag. 15). d) Reconnect power. If the error H2O is no longer displayed, replace the water pressure switch. If the error H2O is still displayed, see below. 3) DEFECTIVE WIRE LEADS OF THE WATER PRESSURE SWITCH Test and remedy: Verify the electrical connection between the main control board and the water pressure switch. Procedure: a) Disconnect the voltage. b) By means of a multimeter, verify the electrical connection between the main control board and the water pressure switch, if interrupted, disconnect the voltage and replace the wire leads. If H20 does not disappear from the display, disconnect the voltage and replace the main control board. 2 Diag. 14 Fig. 10 P R M - 22 - PACQ: Water pressure switch 3Diag. 15
E05 Heating Sensor Malfunction E05 HEATING LOOP TEMPERATURE SENSOR FAILURE CHECK THE HEATING SENSOR VALUE WITH A MULTIMETER REPLACE THE HEATING SENSOR IS THE VALUE CORRECT? (I.E RESISTANCE VALUE 10 KOHM CHECK THE HEATING SENSOR CABLE FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CONTROL BOARD - 23 -
The likely causes are the following: a. HEATING SENSOR DEFECTIVE OR T WORKING PROPERLY Test and remedy: Verify the operation of the heating sensor. Procedure: a) Disconnect the voltage. b) Disconnect the wires from the heating sensor (Fig. 11). c) Set the multimeter to read Ohm s, apply the multimeter teminals to the heating sensor leads. You should have a value of Nominal resistance at 77 F / 25 C 10,000 Ohm, as per the table below. d) If the sensor does not provide the right data, as per the table, replace it. The error E05 will no longer appear on the display when voltage is connected. If the sensor is ok, verify the next point. Fig. 11 2) DEFECTIVE SENSOR Test and remedy: Verify the electrical connection between the main circuit board and the heating sensor. Procedure: a) Disconnect the voltage. b) Disconnect the wire leads of the heating sensor. c) Verify the continuity of the wire leads by means of a multimeter. If it is interrupted, replace the wire leads. The error E05 will no longer appear on the display when voltage is connected. If the wire leads is not interrupted, replace the main circuit board. MINAL RESISTANCE AT 25 C 10,000 Ohm Temp R NTC Temp R NTC Temp R NTC Temp R NTC Temp R NTC Temp R NTC -50 329200-23 78384 4 23014 31 8016 58 3216 85 1451-49 310868-22 74641 5 22069 32 7731 59 3115 86 1411-48 293656-21 71097 6 21168 33 7458 60 3021 87 1373-47 277489-20 67739 7 20309 34 7196 61 2928 88 1336-46 262299-19 64571 8 19489 35 6944 62 2839 89 1300-45 248023-18 61563 9 18706 36 6702 63 2753 90 1266-44 234600-17 58719 10 17959 37 6470 64 2669 91 1232-43 221976-16 56016 11 17245 38 6247 65 2589 92 1199-42 210099-15 53432 12 16563 39 6033 66 2512 93 1168-41 198922-14 51018 13 15912 40 5828 67 2437 94 1137-40 188399-13 48707 14 15289 41 5630 68 2365 95 1109-39 178490-12 46513 15 14694 42 5440 69 2292 96 1079-38 169156-11 44429 16 14126 43 5258 70 2229 97 1051-37 160359-10 42449 17 13582 44 5082 71 2164 98 1024-36 152068-9 40568 18 13062 45 4933 72 2101 99 998-35 144250-8 38780 19 12565 46 4751 73 2040 100 973-34 136876-7 37079 20 12090 47 4590 74 1982 101 948-33 129912-6 35463 21 11634 48 4444 75 1925 102 925-32 123353-5 33925 22 11199 49 4300 76 1870 103 901-31 117154-4 32461 23 10781 50 4161 77 1817 104 879-30 111299-3 31069 24 10382 51 4026 78 1766 105 857-29 105769-2 29743 25 9999 52 3897 79 1717 106 836-28 100544-1 28481 26 9633 53 3773 80 1669 107 815-27 95605 0 27279 27 9281 54 3653 81 1622 108 796-26 90934 1 26136 28 8945 55 3538 82 1577 109 776-25 86518 2 25044 29 8622 56 3426 83 1534 110 757-24 82339 3 24004 30 8313 57 3319 84 1491-24 -
E06 D.H.W. Sensor Malfunction E06 D.H.W. TEMPERATURE SENSOR FAILURE CHECK THE D.H.W. SENSOR VALUE WITH A MULTIMETER REPLACE THE SENSOR IS THE VALUE CORRECT? (I.E RESISTANCE VALUE 10 KOHM CHECK THE D.H.W. SENSOR CABLE FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CONTROL BOARD - 25 -
The likely causes are the following: Diag. 16 b. DOMESTIC SENSOR DEFECTIVE OR T WORKING PROPERLY Test and remedy : Verify the reading of the domestic sensor. Procedure: a) By pressing the lower right button of the control panel (Diag. 16 button 2) for 7 seconds, the domestic output temperature (Diag. 16-3) will be displayed on the LCD screen. If the output temperature, measured by other means, is different from the displayed value, check the sensor resistance. b) Disconnect the voltage. c) Disconnect the wire leads of the domestic sensor (Fig. 12). d) Set the multimeter to read Ohm s, apply the multimeter teminals to the heating sensor leads. You should have a value of Nominal resistance at 77 F / 25 C 10,000 Ohm, as per the table above (see page 24). If the sensor does not provide the right data, as per the table, replace it. The error E06 will no longer appear on the display when voltage is connected. If the sensor is ok, verify the next point 1 3 2 120V 60Hz 2) DEFECTIVE WIRE LEADS OF THE DOMESTIC SENSOR Test and remedy: Verify the electrical connection between the main P.C.B. and the Domestic sensor. Procedure: a) Disconnect the voltage. b) Disconnect the wire leads of the domestic sensor. c) By means of a multimeter, please verify the continuity of the wire leads. If it is interrupted, replace the wire leads. The error E06 will no longer appear on the display when 120v is connected. If the wire leads is not interrupted, replace the main control board. Fig. 12-26 -
E12 D.H.W. Storage Tank Sensor Malfunction E12 D.H.W. Storage Tank Sensor Malfunction CHECK THE STORAGE SENSOR VALUE WITH A MULTIMETER REPLACE THE STORAGE TANK SENSOR IS THE VALUE CORRECT? (I.E RESISTANCE VALUE 10 KOHM AT 25 C CHECK THE STORAGE SENSOR CABLE FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CONTROL BOARD - 27 -
The likely causes are the following: 1) DOMESTIC (STORAGE) SENSOR DEFFECTIVE OR T WORKING CORRECTLY Test and remedy: Verify the operation of the domestic 3 sensor by pressing lower right button Diag. 16 Procedure: d) By pressing the lower right button of the control panel (Diag. 16 button 2) for 7 seconds, the domestic temperature (Diag.16 3) will be displayed on the LCD screen. If the tank temperature, measured by other means, is different from the displayed value, check the sensor resistance. 120V 60Hz e) Using a multimeter, verify the value of the domestic sensor is consistant with the data provided on the table Nominal resistance at 77 F / 25 C 10,000 Ohm (see p.24). If the sensor is working properly, E12 will no longer appear on the display. If E12 continues to appear even after the sensor has been replaced, replace the main contol board. 1 2-28 -
E16 Electric Fan Malfunction E16 E16 Combustion blower Malfunction INDUCED FAN FAILURE CHECK THE OPERATION OF THE FAN REPLACE THE FAN IS THE FAN OPERATING CHECK THE FAN CONTROL CABLE FROM THE MAIN CONTROL BOARD FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CONTROL BOARD - 29 -
M10 The likely causes are the following: 1) COMBUSTION BLOWER DEFECTIVE OR T WORKING PROPERLY Test and remedy: Verify the proper operation of the combustion blower. Procedure: a) Disconnect the wire leads from the combustion blower (Dia. 17 CABLE 1) & (Fig 13). The combustion blower will operate at the maximum speed, if this is the case replace the fan control board (Fig. 14) and the wire leads between that board and the combustion blower. b) If the combustion blower does not activate, ensure 120v is present at the combustion blower. Procedure: a) Disconnect the main wire leads (POWER) of the combustion blower (Dia. 17 CABLE 1) & (Fig 13). b) Using a multimeter, test for 120v on the hot and neutral terminals that feed the combustion blower. In case there is no voltage, verify the 2A fuse, (Fig. 15) which is in series is not open If this is not the case, replace the combustion blower. Fig. 13 Fig. 14 Fig. 15 Diag. 17 Fig.1 PRINTED CIRCUIT BOARD DIGITECH - SM20021 M1 M2 M3 PRINTED CIRCUIT BOARD KOND Fan DT Control - SK11003 Board COD. 76702LA M5 Main Control Board M4 M6 M7 POWER FAN CAVO Cable 11 M8 M8 +24V HS PWM GND M9-30 -
E22 Parameter Programming Request E22 PARAMETER PROGRAMMING REQUEST (THIS CODE APPEARS ON INITIAL POWERING WHEN A MAIN CONTROL BOARD IS CHANGED) MICROPROCESSOR MEMORY IS LOST REPROGRAM PARAMETER SET PARAMETER AS FOUND IN INSTALLATION MANUAL FOR SPECIFIC MODEL AND CAPACITY - 31 -
The likely causes are the following: 1) LOSS OF MEMORY OF THE MICROPROCESSOR OF THE MAIN CIRCUIT BOARD. Test and remedy : Verify all parameters on the main circuit board are as per the original settings. If it is not the case, re-program the unit as per the table included in the technical manual. If the problem still exisits, disconnect the voltage and replace the main circuit board (Fig. 16), as it might have been affected by an irreparable problem with the memory of the micro-processor. When confirming programming make certain you are entering the correct unit capacity and values as the the model you are servicing. (Refer to section 5, Regulating the Appliance) Fig. 1 Fig. 16-32 -
E35 Flame Detection Malfunction E35 Flame Detection Malfunction CHECK THE OPERATION OF THE IONIZATION ELECTRODE / FLAME SENSOR REPLACE THE IONISATION ELECTRODE / FLAME SENSOR IS THE IONISATION ELECTRODE / FLAME SENSOR DEFECTIVE CHECK THE IONISATION ELECTRODE / FLAME SENSOR CABLE FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINUITY REPLACE THE MAIN CONTROL BOARD - 33 -
The likely causes are the following: 1) IONIZATON ELECTRODE / FLAME SENSOR DEFECTIVE OR T WORKING CORRECTLY Test and remedy: Verify the ionisation electrode / flame sensor is operating properly. Procedure: (see side figure) a) Disconnect the voltage from the main electrical supply. b) Close the gas cock. c) Remove the ionisation electrode / flame sensor and verify its integrity. In case it is damaged or broken, replace it. (Replace the gaskets if they are damaged). d) If the ionisation electrode / flame sensor is not broken, disassemble the burner and check by means of a caliper. The ionisation electrode / flame sensor should bear the correct gap to the burner of 9mm ± 1mm. If it is not the case, adjust the gap. If the problem is still exists, replace the ionisation electrode / flame sensor, or finally the main control board. Burner Premix Burner Unit B Primary Heat Exchanger A tyyg gfhg Ionization Electrode / Electrode Flame Sensor / Flame sensor Ignition Electrode Flame sensor Electrode - 34 -
E42 Fan Control Board Malfunction E42 FAN CONTROL BOARD FAILURE CHECK THE CONNECTION CABLE BETWEEN THE MAIN CONTROL BOARD AND THE FAN FOR CONTINUITY OR BREAKS REPLACE THE CABLE IS THERE CONTINIUTY REPLACE THE MAIN CONTROL BOARD - 35 -
M10 The likely causes are the following: 1) THE FAN CONTROL BOARD IS DEFECTIVE OR T WORKING CORRECTLY Test and remedy: Verify the proper running of the fan contol board. Procedure: a) Disconnect the voltage. b) By means of a multimeter, verify the continuity of the wiring wire leads between the main control board and the fan control board (Diag.18 Cable 2) & (Fig. 17). If the electrical connection is interrupted, replace the wire leads (Cable 2). If the electrical connection is not interrupted, replace the fan contol board (Fig. 17). Fig.1 Diag. 18 PRINTED CIRCUIT BOARD DIGITECH - SM20021 M1 M2 M3 PRINTED CIRCUIT BOARD KOND Fan DT Control - SK11003 COD. 76702LA Board M5 M4 Main Control Board M6 M7 CAVO 2 Cable 2 POWER FAN CAVO Cable 1 1 M8 M8 +24V HS PWM GND M9 Fig. 17-36 -
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Function codes Diag. 19 3 Each time flashing numbers are displayed on the LCD display (see Diag. 19 3), a relevant mode is activated. All functions are disabled upon the termination of their specific function. fig.1 1 2 07 Flue Test Function Active (Chimney-Sweeper) Description Pressing the service button for 7 seconds (Diag. 19 button 2) activates the flue test function. Pressing the DPWH ON/OFF switch deactivates the function (Diag.19 button 1). The flue test function operates the DPWH at the maximum heating pressure for 15 minutes without any modulation. The function is useful for combustion testing. 08 Frost Protection Central heating circuit Description This function is activated when the heating sensor senses a temperature of 5 C / 41 F. The DPWH operates at minimum gas pressure with the 3-way diverter valve in the heating position. This function is deactivated when the temperature detected by the sensor when it reaches 30 C / 86 F. 09 Frost Protection D.H.W. circuit Description This function is activated when the sensor senses a temperature of 4 C / 39 F. The DPWH operates at minimum gas pressure. The 3-way diverter valve closes in the domestic position and heats the D.H.W. circuit. This function is deactivated when the D.H.W. storage cylinder sensor detects a temperature of 8 C / 46 F. 13 Frost Protection D.H.W. circuit for storage DPWH Description This function is activated when the sensor senses a temperature of 4 C / 39 F. The DPWH operates at minimum gas pressure. The 3-way diverter valve closes in the domestic position and heats the D.H.W. circuit. This function is deactivated when the D.H.W. storage cylinder sensor detects a temperature of 8 C / 46 F. 28 - Legionella Prevention Function Description This function is activated for storage DPWH only. It comes into operation every 7 days. It brings the hot water temperature in the storage cylinder up to 60 C / 140 F or whatever temperature is set for hot water. 31 Incompatible Remote Control Description This function is activated when the remote control connected is not compatible with the printed circuit board. - 42 -