HEATEC TEC-NOTE. Operation and maintenance Heatec thermal fl uid heaters industrial series IMPOPRTANT NOTICE! CONTENTS. Publication No.

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1 HEATEC TEC-NOTE Operation and maintenance Heatec thermal fl uid heaters industrial series CONTENTS Important Notice...1 Intended users...2 Scope...2 Prior to initial startup...2 Preliminary tasks...2 Purging water from the system...2 Checking limit circuit devices...2 Routine operation...3 Starting and shutting down the heater...3 Cleaning strainers...3 Lubrication...3 Maintenance schedule...4 troubleshooting basics...10 Shock hazards...10 Low media level switch Circulating pump motor auxiliary contacts Low gas pressure switch High gas pressure switch...12 High media temperature controller...12 temperature limits of exhaust gases Combustion air motor auxiliary contacts Low combustion air pressure switch Fuel oil pump auxiliary contacts Low fuel oil pressure switch Pilot gas regulator Figure 2. Heatec vertical helical coil heater. the burner is on its bottom and is up-fi red. Publication No IMPOPRTANT NOTICE! We strongly recommend that you arrange for an experienced fi eld technician from our service department to commission your heater. He will also instruct your operators in the safe operation of your heater. Figure 1. two Heatec horizontal helical coil heaters. One has an output of 60 million Btu/hour. the other has an output of 0.7 million Btu/hour. Figure 3. Heatec 3-pass vertical heater. Its burner is on its top and is down-fi red.

2 Intended users Information in this document is intended for use by plant personnel responsible for operation and maintenance of your new Heatec heater. Scope This Tec-Note outlines the tasks that must be performed for initial startup (commissioning) of your Heatec helical coil heater. It also covers routine operation, maintenance and troubleshooting. It applies to Heatec industrial series of heaters that heat thermal fluid. We make these heaters in various configurations and sizes according to customer specifications and preferences. (See Figures 1, 2, and 3.) Consequently, most have significant differences in components, differences in piping systems and differences in their use. Because of these differences, some information in this document omits details on how to perform the tasks. Moreover, the figures shown are for a typical heater and may differ significantly from your particular unit. But despite differences, information herein gives a preview of what commissioning entails and serves as a guide for the tasks covered. Our field technician will thoroughly cover the details of your particular heater when he commissions it. Interchangeable terms The terms media, thermal fluid and hot oil are used interchangeably. All three refer to the same thing. Prior to initial startup Please read the safety information shown in Heatec Tec-Note It is the first Tec-Note in this manual. The following tasks should be done prior to initial startup and prior to arrival of the person who will commission your heater: The incoming gas supply line pressure should match the pressure shown on the P&ID drawing furnished with the heater. The heater should be properly installed, piped, and wired. The control panel should be checked for proper supply voltage and for proper control voltage. The equipment that is to be heated by thermal fluid should be fully piped and leak-tested. The thermal fluid circuit should be filled with thermal fluid. Thermal fluid strainers should be cleaned after the system is filled. Preliminary tasks: When a Heatec technician commissions your heater, he will perform the following tasks before initial startup of your heater: 1. Make sure the valves for differential pressure switch(es) are open. 2. Make sure that sight gauge valves are open. 3. Turn on all breakers inside the control panel. 4. Lockout electrical power at the control panel and check thermal fluid pumps for proper alignment and free rotation of their shafts. 5. Restore power to the control panel and purge air from thermal fluid pumps. 6. Check all devices in the 3-P limit circuit. 7. Set up the temperature controllers on the control panel with their appropriate settings. Initial settings for purging water from the system are as follows: Set point of modulating controller is 230 degrees F. Set point of high media temperature controller is 280 degrees F. Purging water from the system The Heatec technician will purge water from your thermal fluid system as part of the commissioning operation. This task requires firing the burner and heating the thermal fluid. Note: The burner on your heater must be tuned after the heater is installed at your facility for local altitude conditions. The Heatec technician that commissions your heater will do that. If you do not plan to have a Heatec technician to commission your heater, you should have a qualified burner technician to perform the initial startup of the burner and tune it for the local altitude conditions. Purging the system can take from two hours to two days or longer, depending on the amount of thermal fluid in the system and the amount of water in the thermal fluid. Purging water from the thermal fluid system involves venting the expansion tank to atmosphere and boiling out the water entrained in the thermal fluid. This is done using the modulation controller to gradually raise the temperature of the thermal fluid from 230 degrees F to about 20 degrees above operating setpoint (PV) in increments of 10 degrees. The high media temperature controller must also be reset about 50 degrees higher than the modulation controller each time the modulation controller is reset. Before purging, valves must be set to circulate the thermal fluid through the expansion tank as it circulates through the system. After purging, the temperature controllers and valves must be reset for normal operation. Page 2 Publication No

3 Routine operation After your heater has been commissioned, your operators can take over its routine operation, maintenance and troubleshooting. Instructions for those tasks are included in the remainder of this document. Starting and shutting down the heater (Fig. 9) 1. To start the heater, turn on the thermal fluid pump and the burner. 2. To shut down the heater, turn off the burner and the thermal fluid pump. Cleaning strainers (F, Fig. 7) 1. Shutdown the heater. 2. Allow the heater and its thermal fluid to cool down.!warning Wear appropriate protective gloves and clothing suitable for handling liquids with temperatures of 350 degrees F or more. Contact with hot thermal fluid can cause severe burns. Handle it with extreme care to avoid contact or spills. 3. Set all valves to mode for Clean Strainer (Fig. 4). 4. Place a bucket or other container (with a capacity of at least 5 gallons) under each strainer drain. 5. Open drain valves to drain thermal fluid from the strainers. Do not re-use this fluid. Dispose of it according to applicable codes. 6. Unbolt the square flange from the bottom of the strainer. Remove the flange, allowing the strainer basket to slide out. 7. Clean the strainer basket. 8. Re-install the strainer basket. 9. Close drain valves. 10. Set valves to mode for RUN as indicated in Figure 4. Lubrication All Heatec heaters have components that require periodic lubrication. Figure 5 lists the components and the recommended lubricants. Maintenance schedule The next page of this document provides a list of items that should be checked periodically to ensure safe, troublefree operation of your Heatec heater. Figure 4. Valve settings for operating modes. Valves in heater thermal fluid piping Operating mode Purge Block Valve A, Fig. 7 Inlet Valves E, Fig. 7 Purge Valve B, Fig. 7 Expansion Valve D, Fig. 7 Discharge Valves K, Fig. 7 Run Open Open Closed Open Open Purge Closed Open Open Open Open Clean Strainer Open Closed Closed Open Closed Figure 5. Lubrication requirements. See Fig. 7 Name Lubricant Frequency (all valves) Valves with grease fittings High temp lithium grease monthly H Thermal fluid pumps High temp lithium grease 2800 hrs operation I Thermal fluid pump motors High temp lithium grease 3 months (NOT SHOWN) Modulating actuator linkage joints General purpose oil monthly Page 3 Publication No

4 MAINTENANCE SCHEDULE Heatec heaters should be checked periodically according to the requirements below. Failure to properly maintain your heater could result in a fire or explosion. REQUIREMENT WEEKLY MONTHLY QUARTERLY YEARLY Check for proper level of thermal fluid. Sight gauge on expansion tank should show at least 3 inches. Clean ultraviolet flame detector lens. Check intake area of blower to make sure it is not blocked by foreign material and is free from buildup of dirt. Check flame to ensure burner shows no symptoms of being in need of tuning. During normal operation check all pressure gauges and thermometers on heater for normal values. Check all operating and limit controls and settings to make sure they are set properly and are working properly. Check strainers to ensure they are not dirty. Check heater and piping to ensure there are no leaks of thermal fluid. Check heater to ensure there is no structural damage to heater shell, end plates, etc. or signs of over heating. Check pilot assembly to make sure spark gap is 1/8 to 3/16 inch. Check burner control linkage to make sure it is not binding or loose. Have exhaust stack gases analyzed and have burner tuned by a specialist Have thermal fluid analyzed to ensure it is not degraded. Lubricate heater components, including linkage, valves, motors, pumps. (Lubricate monthly or as recommended by the manufacturer.) Check fuel gas strainer (Y, Fig. 8) to ensure it is not dirty. Page 4 Publication No

5 A B C D E F Q P O N M L K J A. B. C. D. E. F. G. H. I. I Level gauge Expansion tank Vent/fill connection Nitrogen connection Purge line Expansion line Pump skid (see Figure 7) Differential pressure switch Combustion air filter/silencer H J. K. L. M. N. O. P. Q. G Combustion air blower Fuel train (see Figure 8) Burner Economizer thermal fluid outlet Economizer Economizer thermal fluid inlet Exhaust stack Screen and rain cap Figure 6. Typical industrial heater. Page 5 Publication No

6 A B L K J E D C F G I H A. Purge block valve B. Purge valve C. Thermal fluid return inlet D. Expansion valve E. Inlet valves F. Strainers with drains G. Inlet pressure/vacuum gauges H. Thermal fluid pumps I. Pump motors J. Discharge pressure gauges K. Discharge valves L. Check valves NOTE This pump skid is shown with two sets of pumps and associated components. One serves as a primary while the other serves as a backup or alternate. Both are not normally operated simultaneously. The control panel has separate controls for each pump. The controls and wiring diagrams are labeled to distinguish the two pumps from each other. The pumps should be labeled to match the controls when the heater is installed. Figure 7. Pump skid with two pumps. Page 6 Publication No

7 A B C D E F G H I J K L TO BURNER Z Y W V U T S R Q P O N M A. Pilot manual block valve B. Pilot gas regulator C. Pilot pressure gauge and isolation valve D. Pressure test connection P1 E. Secondary pilot shutdown valve F. Pilot vent valve G. Pressure test connection P2 H. Pilot primary shutdown valve I. Pressure test connection P3 J. Primary manual block valve K. Ratio regulator L. Limiting orfice M. Pressure test connection M4 N. Pressure gauge O. High gas pressure switch P. Primary shutdown valve Q. Normally open vent valve R. Pressure test connection M2 S. Secondary shutdown valve T. Pressure test connection M1 U. Low gas pressure switch V. Main pressure gauge and isolation valve W. Relief valve (when required). Main Gas (trim) regulator Y. Y-strainer Z. Secondary manual block valve Figure 8. Fuel train. Page 7 Publication No

8 BURNER DISPLAY MODULATING CONTROLLER A BLV512 B NET BACK MODE RESET MDFY C OFF N HIGH MEDIA TEMPERATURE CONTROLLER HIGH STACK TEMPERATURE CONTROLLER D RESET OPEN M E OFF ON L POWER ON BURNER F K HEATER ALARM PUMP P1A RUNNING G P1A OFF P1B J ALARM SILENCE PUMP SELECTOR H HOLD NORMAL LOW FIRE HOLD PUMP P1B RUNNING I EMERGENCY-STOP EMERGENCY-STOP A. Burner management control B. Burner modulating controller C. Power disconnect switch D. High stack temperature controller E. Burner switch F. Pump P1A running indicator light G. Pump selector switch H. Pump P1B running indicator light I. Emergency stop switch J. Low fi re hold switch K. Alarm silence switch L. Heater alarm silence indicator light M. Power indicator light N. High media temperature controller NOTE: Separate controls are provided for the two heater pumps. The controls and wiring diagrams are labeled to distinguish the two pumps from each other. However, their designations may vary from one heater to another. In any case, the pumps should be always be labeled to match the controls when the heater is installed. Figure 9. Operating controls. Page 8 Publication No

9 L A K B C D E F J G I H A. Breaker auxiliary contacts for fuel oil pump motor B. Breaker auxiliary contacts for combustion air blower motor C. Breaker disconnect for combustion air blower motor D. Breaker disconnect for fuel oil pump motor E. Contactor for combustion air blower motor F. Auxiliary contacts for combustion air blower motor G. H. I. J. Auxiliary contacts for fuel oil pump motor Contactor for fuel oil pump motor Contactor for media circulating pump motor Auxiliary contacts for media circulating pump motor K. Breaker disconnect for media circulating pump motor L. Breaker auxiliary contacts for media circulating pump motor Figure 10. Components of motor controllers inside the control panel. Page 9

10 Troubleshooting basics Although troubleshooting is something you normally do only after your heater has a problem, it is useful to gain knowledge of how things work beforehand. We recommend that you get familiar with the information in this document without waiting for a problem to develop. Most of the devices covered in this document are incorporated in the heater s 3 P interlock circuit. Each of these devices is intended to detect a specific abnormal operating condition. If any of these devices encounters the abnormal condition for which it is intended, it will shut down the burner and activate the heater s warning system. On some heaters the warning system uses a red light on top of the panel. It flashes when an abnormal condition triggers a shutdown. Other heaters use an audible alarm. The heater may also be wired into a remote control system that indicates an abnormal shutdown. You must find and fix the problem before you can restart the heater. If a shutdown happens you will see a LOCKOUT message on the burner display (Fig. 9). The first line of the message indicates the operating condition when the lockout happened. The second line indicates what abnormal condition triggered the lockout. The lockout message may identify one of the limit devices in the 3 P interlock circuit as the cause of the shutdown. A clogged strainer is often the source of one or more abnormal conditions that will open an interlock device in the 3 P circuit. It can cause high media temperature. It can cause high stack temperature. And it can cause inadequate pressure differential across the coil. Improper settings of a differential pressure switch is also a common cause of 3 P interlock shutdowns. Lockout messages on the burner display may indicate that a shutdown was caused by abnormal conditions not related to the 3 P circuit. A message that says M-8 LIMIT OPEN is usually caused by a problem with the burner modulation motor. A message that says LOCKOUT STANDBY FALSE FLAME usually indicates a faulty flame scanner (when there is really not a flame in the burner). A message that says LOCKOUT PTFI FLAME FAIL is usually caused by a problem with the flame scanner, or with fuel, or with ignition. A message that says LOCKOUT AUTO FLAME FAIL is usually caused by a problem with fuel or combustion air. There is also the possibility that an interlock device itself has malfunctioned and has caused a shutdown. Or there may be yet another cause. In reality, troubleshooting is a process of elimination that starts with the lockout message. For example, assume the burner shuts down and the display says LOCKOUT LO MEDIA LEVEL. Obviously, the first thing to do is to check the level of thermal fluid in the expansion tank. If it is actually too low, fixing the problem may be as simple as adding thermal fluid to the system and making sure there is no leak in the piping system. If it is not too low, the next thing to check is the media level switch located in the expansion tank. If the switch is okay the problem is almost certainly to be a faulty wiring connection or relay. The information in this document should enable you to determine whether various interlock circuit devices are working properly. Shock hazards Troubleshooting instructions in this document are intended for use by plant personnel who understand electrical shock hazards and how to avoid them. Such persons should also know about the usual burn hazards present when working with thermal fluids heated to temperatures in excess of 300 degrees F. Some procedures require making electrical tests and settings inside the heater electrical control panel while it is open and electrical power is turned on. This should be done only by persons authorized by their employer to work inside panels while significant electrical hazards are present. Employers and/or owners should have prescribed safety procedures for such work. Page 10 Publication No

11 Low media level switch This switch (Fig. 11) shuts down the burner if the level of media in the expansion tank gets too low for safe operation. The switch is wired into the 3 P interlock circuit. escape. There is no opening between the float housing and the switch housing. (The float mechanism has a magnet that activates the switch inside the switch housing.) You can open or replace the switch housing without draining the expansion tank. However, you must drain the tank before removing the float housing. If the first check determines that the switch is working when closed, proceed with the second check to ensure that opening its contacts will shut down the burner. Remove the switch cover. Use the flat side of a screwdriver to depress the trip mechanism so as to open the switch contacts (Fig. 12). Figure 11. Low media level switch. Before checking the switch for proper operation, confirm that the expansion tank (B, Fig. 6) contains an adequate level of thermal fluid media. Do this by viewing the level gauge (A, Fig. 6). to make sure the level of the fluid is above the spot where the switch is installed in the tank. Also verify that the float inside the tank is properly oriented by checking the bushing at the back of switch on the outside of the tank. One of the six flat sides of the hex on the bushing should be stamped with the letter T. This flat side of the bushing should be on top and should appear to be level. There are two checks that you should make to determine if the switch circuit is working properly. The first check determines if the switch contacts are actually closed as they should be when there is an adequate level of media in the expansion tank. The second check makes sure that opening the switch contacts will actually shutdown the burner as it should. To do the first check, open the control panel (Fig. 9) and turn on power to the panel while it is open. Locate the two terminals where the level switch wires are connected. Check for 120 VAC between each terminal and neutral. If the voltage is present at both terminals, the switch is closed and is working properly. If voltage is present on one of the terminals, but not the other, the switch circuit is open and there is a problem with the switch circuit. Remove the screw-on cover plate from the back of the switch and see if there is a loose wire or an obvious problem with the micro-switch or the linkage that activates the switch. Otherwise, replace the entire switch, including the float portion. Note: The switch has two parts: a switch housing and a float housing. The float housing protrudes inside the tank and seals the opening so that thermal fluid cannot Figure 12. Opening the contacts of a low media level switch. Opening the switch should cause the following reactions, which indicate that the switch is operating properly: 1. Circulating pump should shut off. 2. The burner should shut down. 3. The message on the bottom line of the Fireye display module should read LOCKOUT LOW MEDIA LEVEL. Circulating pump motor auxiliary contacts This is a module with contacts (J, Fig. 10) that prevent operation of the burner unless the contactor for the media circulating pump motor is actuated (closed). The contacts are wired into the 3 P interlock circuit. The module has a plunger that opens and closes the contacts by engagement with the contactor. If the contactor opens, its plunger will open the contacts and shut off the burner. Check the auxiliary contacts as follows: With the burner operating, trip the breaker disconnect for the media circulating pump motor (K, Fig. 10). Page 11

12 This should cause the auxiliary contacts to open. The following reactions should occur, indicating that the contacts are operating properly: 2. The message on the bottom line of the Fireye display module should read CIRC PUMP AU CT. Reset circulating pump circuit breaker. Low gas pressure switch This switch (U, Fig. 8) shuts down the burner if the gas pressure goes lower than the setpoint on the switch. The switch is wired into the 3 P interlock circuit. Check the switch as follows: Shut off the primary manual block valve (J, Fig. 8) and set BURNER switch (E, Fig. 9) to ON. Remove the plug from pressure test connection M1 (T, Fig. 8) below the pressure switch. Open its valve allowing gas to escape. The following reactions should occur, indicating that the switch is operating properly: The display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT 3 P INTLK OPEN. Reinstall plug in the connection. Slowly re-open the primary manual block valve (J, Fig. 8). The low gas pressure switch (U, Fig. 8) should automatically reset. Reset the Fireye control (A, Fig. 9). High gas pressure switch This switch (O, Fig. 8) shuts down the burner if the gas pressure increases higher than the setpoint on the switch. The switch is wired into the 3 P interlock circuit. Check the switch as follows: With the burner operating, remove the cover from the switch. Be careful not to touch the live terminals. Adjust the switch to a lower setting that causes the switch to open. The following reactions should occur, indicating that the pressure switch is operating properly: The burner should shut down. The display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT 3 P INTLK OPEN. Re-adjust the high pressure switch to its previous position. The switch should automatically reset. Reinstall its cover. High media temperature controller This controller (N, Fig. 9) shuts down the burner if the media temperature exceeds its setpoint. The temperature controller is manually preset to a set point (SP) that has been established by the customer for the individual heater. It can be changed in the field by an operator. The controller monitors the temperature signal from a thermocouple mounted in the outlet of the helical coil. Check the controller as follows: With the burner operating, note the PV (process variable) temperature shown on the high media temperature controller (N, Fig. 9). Change the SP (setpoint) to a value lower than the temperature noted. The following reactions should occur, indicating that the controller is operating properly: 2. The message on the display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT HI MEDIA TEMP. Be sure to reset the controller to its previous setpoint and push SET/ENT button. Depress and hold the reset button on the controller for 3 seconds. Temperature limits of exhaust gases Each heater has a system to shut down the burner if the heater exhaust gas exceeds preset limits. Two different systems are used. One system employs a thermocouple and a temperature controller (D, Fig. 9) which can be adjusted in the field. The other system uses a temperature switch (Fig. 13) instead of a thermocouple and controller. The operating temperature of the switch should not be adjusted in the field. The temperature controller (D, Fig. 9) is manually preset to a set point (SP) that has been established by the customer for the individual heater. It can be changed in the field by an operator. The controller monitors the temperature signal from the thermocouple, which is mounted in the exhaust stack. If the temperature of the exhaust gas exceeds the set point, the controller will open the interlock circuit and shutdown the burner. The controller and thermocouple can be checked for proper operation as described below. With the burner operating, note the PV (process variable) temperature shown on the high stack temperature controller (D, Fig. 9). Change the SP (setpoint) to a value lower than the temperature noted and push the SET/ENT button. Page 12

13 The following reactions should occur, indicating that the controller is operating properly: 2. The message on on the display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT HI STACK TEMP. Be sure to reset the controller to its previous setpoint and push SET/ENT button. Depress and hold the reset button on the controller for 3 seconds. Temperature switches are preset by the manufacturer to open at a specified temperature. We usually order them set for 1,000 degrees F. Although they can be ordered for other temperatures, they should not be changed in the field. The switch is wired into the 3 P interlock circuit. If the temperature of the exhaust gas exceeds the preset temperature, the switch will open the interlock circuit and shutdown the burner. The switch can be checked for proper operation as described below. With the burner operating, remove cover from the high flue gas temperature switch. Use the flat side of a screwdriver to depress the tiny button on the switch to open its contacts (Fig. 13). Be careful not to touch live terminals on the switch. The following reactions should occur, indicating that the switch is operating properly: 2. The message on on the display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT HI STACK TEMP. Reset the switch, using the insulated handle of a screwdriver to press the reset button on the switch. This avoids the possibility of electrical shock from the exposed terminals next to the reset button. Combustion air motor auxiliary contacts This is a module with contacts that prevent operation of the burner unless the contactor for the combustion air motor is actuated (closed). The contacts are wired into the 3 P interlock circuit. The module has a plunger that opens and closes the contacts by engagement with the contactor. If the contactor opens, its plunger will open the contacts and shut off the burner. Check the auxiliary contacts as follows: With the burner operating, trip the breaker disconnect for the combustion air blower motor (C, Fig. 10). This should cause its auxiliary contacts (F Fig. 10) to open. The following reactions should occur, indicating that the contacts are operating properly: 2. The display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT AIR AU CT. Reset the breaker disconnect for the combustion air blower motor. RESET BUTTON Figure 13. Checking high flue gas stack temperature switch. Page 13

14 Low combustion air pressure switch This switch (Fig. 14) shuts down the burner if combustion air is too low for safe operation. The switch is wired into the 3 P interlock circuit. Figure 14. Low combustion air switch. Check the switch as follows: With the burner off, unlatch the auxiliary contacts module and physically remove it from the burner circuit breaker with wires attached. Pull out the blue plunger on the module (Fig. 15) and hold it out so as to close its contacts. Fuel oil pump auxiliary contacts This is a module with contacts that prevent operation of the burner unless the contactor for the fuel oil pump motor is actuated (closed). The contacts are wired into the 3 P interlock circuit. The module has a plunger that opens and closes the contacts by engagement with the contactor. If the contactor opens, its plunger will open the contacts and shut off the burner. Check the auxiliary contacts as follows: With the burner operating, trip the breaker disconnect for the fuel oil pump motor. This should cause the auxiliary contacts to open. The following reactions should occur, indicating that the contacts are operating properly: 2. The display on the Fireye burner management control (A, Fig. 9) should read FUEL PUMP AU CT. Reset fuel pump circuit breaker. Low fuel oil pressure switch This switch (Fig. 16) shuts down the burner if fuel oil pressure is too low. The switch is wired into the 3 P interlock circuit. switch Figure 15. Pulling out plunger on an auxiliary contacts module. Restart the burner. Trip the burner circuit breaker. The following reactions should occur, indicating that the pressure switch is operating properly: 2. The display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT LO AIR PRES. Re-insert the auxiliary contacts module into the breaker disconnect. Figure 16. Low fuel oil pressure switch. Check the switch as follows: With the burner off, unlatch the auxiliary contacts module and physically remove it from the fuel pump circuit breaker with wires attached. Pull out the blue plunger on the module (Fig. 15) and hold it out so as to close its contacts. Page 14

15 Restart the burner. Trip the fuel pump circuit breaker. The following reactions should occur, indicating that the pressure switch is operating properly: 2. The display on the Fireye burner management control (A, Fig. 9) should read LOCKOUT LO FUEL PRES. Pilot gas regulator This regulator (B, Fig. 8) controls pressure of the pilot gas. Its switch is not wired into the 3 P interlock circuit. Check the regulator as follows: 1. Make sure that pressure in gas supply line is according to that specified in the applicable P&ID drawing. To check the pressure, connect a pressure gauge in place of the plug in the bottom of the Y-strainer (Y, Fig. 8). 2. Connect a manometer to pressure test connection (I, Fig. 8). 3. Start the burner. When Fireye flame monitor indicates PTFI, check to see that the pressure on the manometer is 6 to 8 inches WC. If not, remove cap from pilot gas regulator and adjust the regulator to attain this presure. NOTE: Some burners require pilot pressures other than 6 to 8 inches. Be sure to check the burner manufacturer s specifications for the pilot pressure required for the burner on your heater. Heatec, Inc Wilson Road Chattanooga, Tennessee (423) (800) Fax (423) Heatec, Inc. Page 15