HEATEC TEC-NOTE STARTUP HC AND HCS SERIES HELICAL COIL HEATERS

Transcription

1 RESET MDFY Part No Part No HEATEC TEC-NOTE STARTUP Revised HC AND HCS SERIES HELICAL COIL HEATERS SAFETY Before starting your heater please read the safety information shown in Heatec Tec-Note It is the first Tec- Note in this manual. Then read this entire document before performing any of the instructions. Do not deviate from these startup instructions. Perform step-by-step instructions in the order given. Otherwise you could create unforeseen safety hazards. Scope This Tec-Note provides step-by-step instructions for startup of HC and HCS heaters (Fig. 1) that have the burner management controls shown in Figure 2. These are the current controls used on these heater models. You can find detailed information on these controls in Heatec Tec-Note This Tec-Note supersedes Tec-Note , which covers startup of earlier models with different controls. NOTE: HC heaters have a manifold and auxiliary (side) pumps that distribute thermal fluid to multiple circuits that are independently controlled. HCS heaters do not have a manifold, but have a single circuit that circulates fluid through the heater, tanks and other equipment being heated (Fig. 1 and 5). Intended users Instructions in this document are intended for use by asphalt 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 liquid asphalt and 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. Figure 1. Heatec HCS heater with new control panel. BURNER MODULATION CONTROLLER MODE NEXT BACK MEDIA HIGH-TEMPERATURE CONTROLLER BURNER DISPLAY ABNORMAL SHUTDOWNS BLV512 GAS OIL OFF ON OFF ON DANGER FUEL SELECTOR CIRCULATING PUMP BURNER PART NO SHOCK HAZARD. Hazardous voltage is present inside this panel. Contact with it will cause death or serious injury. Disconnect and lock out electrical power to this panel before opening the panel door. OFF ON OFF ON OFF ON AUXILIARY PUMP #1 AUXILIARY PUMP #2 AUXILIARY PUMP #3 PELIGRO RIESGO DE ELECTROCUCION. Hay niveles peligrosos de voltaje dentro de este tablero. El contacto causará la muerte o lesiones graves. Desconectar y bloquear la alimentación eléctrica suministrada a este tablero antes de abrir su puerta. If the heater encounters an abnormal operating condition it will shutdown and the red light on top of the Improper settings of the two pressure differential inadequate pressure differential across the coil. panel will flash. You must find and fix the problem switches are also a common cause of 3-P interlock To ensure that the flame scanner is working properly, before you can restart the heater. shutdowns. manually restart the heater twice daily. If the scanner is not working properly it will prevent a restart and If a shutdown happens you will see a LOCKOUT message on the burner display. that a shutdown was caused by abnormal conditions temporarily to restart the heater. That would would Lockout messages on the burner display may indicate should be replaced. Never disconnect the scanner prevent it from shutting off fuel in case of a flame not related to the 3-P circuit. A message that says M-8 The first line of the message indicates the operating failure. This could cause an explosion and fire, causing injury or death. LIMIT OPEN is usually caused by a problem with the condition when the lockout happened. The second line burner modulation motor. indicates what abnormal condition triggered the lockout. A message that says LOCKOUT STANDBY FALSE FLAME usually indicates a faulty flame scanner (when The lockout message may identify one of the limit there is really not a flame in the burner). Para asegurar que el explorador de llamas funciona devices in the 3-P interlock circuit as the cause of the correctamente, rearrancar el calentador manualmente shutdown. A message that says LOCKOUT PTFI FLAME FAIL is dos veces por día. Si el explorador no funciona usually caused by a problem with the flame scanner, correctamente, se impedirá el rearranque de la unidad. A clogged strainer is often the source of one or more or with fuel, or with ignition. En tal caso, sustituirlo. Nunca desconectar el explorador de modo temporal para poder rearrancar el calenta- abnormal conditions that will open an interlock device in the 3 P circuit. It can cause high media temperature. A message that says LOCKOUT AUTO FLAME FAIL is dor porque entonces no se cortaría el suministro de It can cause high stack temperature. And it can cause usually caused by a problem with fuel or combustion combustible en caso de apagarse la llama. Esto podría ocasionar una explosión o incendio y causar lesiones air. personales o la muerte. PART NO Figure 2. New control panel.

2 Prior to startup The following conditions are required prior to startup: The incoming gas supply line pressure is 1 psig max. You have a propane bottle to use for the gas pilot on combination gas-oil burners if gas is shut off. Gas pressure to the pilot regulator should not exceed 10 psi. The heater is properly installed, piped, and wired. The equipment that is to be heated by thermal fluid is fully piped and leak-tested. There is no thermal fluid in the heater or in its piping circuits. Figure 3. Emergency stop and power disconnect switches. Preliminary procedure: 1. Make sure the power disconnect switch (the handle) on the control panel (Fig. 3) is set to OFF. 2. Make sure the switches marked BURNER and CIRCULATING PUMP are set to OFF (Fig. 4). 3. For HC heaters, make sure all switches marked AUXILIARY PUMP are set to OFF (Fig. 4). 4. If heater operates on gas only, remove fuel pump coupling. Please refer to separate Tec-Note on Servicing for procedure for removing the coupling. 5. Make sure the two shutoff valves for high and low media pressure switch are open (Fig. 6). 6. Make sure the two shutoff valves on the sight gauge (Fig. 7) are open. 7. Install drain valve (Fig. 8) (not supplied) in the plug port of the strainer (M, Fig. 5). Be sure to coat threads with a high temperature pipe thread sealant such as Rectorseal No. 5. Improperly sealed threads will result in leakage of thermal fluid. 8. The next 3 steps instruct you to work inside of the heater control panel while its parts are electrically energized with high voltage. You will need a voltmeter suitable for measuring up to 600 volts AC. DANGER! Perform these steps only if you are authorized by your company to work inside electrical panels while energized. Follow all of your company s safety procedures, especially those pertaining to arc flash. Do not touch live or energized terminals. Wear a face shield, protective clothing and insulated gloves while working in the panel. You could be killed or seriously injured if you fail to take these precautions. 9. the control panel and turn on all breakers except main disconnect breaker. There are four toggle breakers and two rotary breakers. HC heaters have an additional rotary breaker for each auxiliary pump. 10. Check for 480 vac across the terminals at the top of the main disconnect circuit breaker (Fig. 12). Manually turn on the main circuit breaker and check for 480 vac across the terminals at the bottom of the breaker. Check for 120 vac across the secondary winding of the control transformer (Fig. 13). 11. Make sure that the EMERGENCY STOP control (Fig. 3) on the control panel operates properly. While power is ON, open the panel and check for 120 vac across terminals 1 and 2 inside the control panel. Push in the control. A light should come on inside the stop control. Now check to make sure there is no voltage across terminals 1 and 2. Reset the stop control and close the panel door. 12. On all thermal fluid pumps, temporarily remove guard that covers pump coupling and check that pump shaft is properly aligned with motor shaft. Rotate shaft by hand to make sure that pump is free to turn. Perform alignment in accordance with applicable instructions published by the pump manufacturer. If you do not have a copy of the instructions, please contact Heatec to obtain a free copy. 13. Purge air from the seal chamber of all thermal fluid pumps according to the pump manufacturer s instructions furnished with the heater. 14. Set the temperature controllers per instructions that follow. Page 2

3 BLV512 BURNER MODULATION CONTROLLER MEDIA HIGH-TEMPERATURE CONTROLLER RESET NEXT MODE BACK MDFY BURNER DISPLAY GAS OIL OFF ON OFF ON FUEL SELECTOR CIRCULATING PUMP BURNER PART NO OFF ON OFF ON OFF ON AUXILIARY PUMP #1 AUXILIARY PUMP #2 AUXILIARY PUMP #3 PART NO Figure 4. Operating controls for HC heater are shown. Controls for HCS heaters are the same except they do not have auxiliary pump switches. Page 3

4 A B C P A. B. C. D. E. F. G. H. O N L M Expansion tank Expansion tank filler Heater end cover plate Outlet from helical coil Valve No. 2 (purge) Thermal fluid return inlet Valve No. 3 (expansion) Inlet pressure gauge I. J. K. L. M. N. O. P. Figure 5. Location of components on RH side of HCS heater. K Page 4 J I H G F Pressure differential switch Outlet pressure gauge Valve No. 1 (strainer) Inlet pressure gauge port Strainer Valve No. 4 (coil inlet) Burner fan motor Circulating pump E D

5 COIL INLET PRESSURE GAUGE PRESSURE DIFFERENTIAL SWITCH COIL OUTLET PRESSURE GAUGE COIL OUTLET CONNECTION COIL INLET CONNECTION THESE TWO VALVES SHOULD ALWAYS REMAIN OPEN WHILE HEATER IS IN SERVICE Figure 7. Sight gauge. Figure 6. UE pressure differential switch 4W3A01-K-13. PILOT GAS MANUAL SHUTOFF VALVE Figure 8. Drain valve in strainer flange. Wear chemical and heat resistant gloves as protection from hot oil. SECONDARY GAS MANUAL SHUTOFF VALVE MAIN GAS MANUAL SHUTOFF VALVE Figure 9. Controls on LH side of burner. Operating mode Run Purge Clean Strainer Valves on heater thermal fluid piping Valve No. 1 Valve No. 2 Valve No. 3 Valve No. 4 Figure 10. Valve settings for operating modes. Modulating Controller set point 320 degrees F 350 degrees F 370 degrees F Figure 12. Main disconnect circuit breaker. High Temp. Controller set point HCS Heater HC Heater 370 degrees F 400 degrees F 400 degrees F 430 degrees F 420 degrees F 450 degrees F (Normally 50 degrees F higher than set point on Modulating Controller (Normally 80 degrees F higher than set point on Modulating Controller) Figure 11. Suggested set points for Media High Temp. Controller. Page 5 Figure 13. Control transformer.

6 Setting temperature controllers 1. Set the power disconnect switch (the handle) on the control panel (Fig. 3) to ON. Displays of the burner and the two controllers should come on. 2. Check the settings of the BURNER MODULATION CONTROLLER and MEDIA HIGH TEMPERATURE CONTROLLER (Fig. 4) to make sure they are programmed according to the instructions in applicable Heatec Tec-Notes. 3 Adjust the set point on the BURNER MODULATION CONTROLLER (Fig. 4) to 230 degrees F. To adjust set point, use the up-down arrows on the controller. Do not adjust the set point above 230 degrees F at this time. 4. Adjust the set point on the MEDIA HIGH TEMPERATURE CONTROLLER (Fig. 4) to 280 degrees F. The MEDIA HIGH TEMPERATURE CONTROLLER shuts down the heater if the temperature of the thermal fluid reaches this set point. 5. Set the power disconnect switch (the handle) on the control panel (Fig. 3) to OFF. HCS heaters filling fluid circuit with thermal fluid This procedure applies to HCS heaters used for heating systems with a single thermal fluid circuit. The procedure assumes the use of a transfer pump to pump the thermal fluid from its shipping containers into the expansion tank of the heater. Consequently, after the circuit is filled, any excess fluid in the expansion tank can be pumped back into the containers. If you don t have a transfer pump you must take extra care not to overfill the system. Otherwise, you may have difficulty removing excess fluid from the expansion tank. This procedure can take 2 hours or longer, depending on the size of the system. 1. Set the power disconnect switch (the handle) on the control panel (Fig. 3) to ON. 2. Set valves as indicated in Fig. 10 for purge. 3. Make sure all valves in the thermal fluid circuit that is connected to the heater are open. 4. Make sure drain valve (Fig. 8) is closed. 5. Remove the cap from the expansion tank filler (B, Fig. 5). Pump thermal fluid from the shipping containers into the expansion tank until the tank is full. Leave the cap off of the expansion tank filler. Excess air will exit through this opening as you circulate fluid. 6. Momentarily set switch marked CIRCULATING PUMP to ON and check the circulating pump motor for proper rotation as marked on pump housing. 7. Set the switch labeled CIRCULATING PUMP to ON (Fig. 4). The circulating pump (P, Fig. 5) should begin to operate. The pump may cavitate intermittently as trapped air escapes from the system. Cavitation can be recognized by a rattling sound. Another indication of cavitation is oscillation of the pressure gauge at the inlet of the coil (Fig. 6). If cavitation does not stop after a few seconds, momentarily close and open valve #4 (N, Fig.5) until cavitation stops and pressure shown on the gauge at the coil inlet (Fig. 6) stabilizes. Note: If the circulation pump continues to cavitate, check the pressure gauge at the inlet of the coil. If the gauge indicates a continuing drop in pressure, the strainer may be clogged. In that case, shut off the circulating pump and clean the strainer. You may have to clean the strainer several times during start-up. 8. Observe fluid level in the sight gauge. When its level drops to about 3 inches, set the switch labeled CIRCULATING PUMP to OFF (Fig. 4). This is a precaution to avoid drawing air into the system. 9. Repeat the previous steps of filling the tank and operating the circulation pump until the system is full. You will know the system is full when the level in the sight gauge does not drop when the circulation pump is operated. 10. When the system is full make sure the fluid level in the expansion tank is 3 to 4 inches as indicated on the sight gauge. This is the normal cold fluid level. If the level is higher than 3 to 4 inches, pump excess fluid out of the tank back into the original containers. 11. Replace cap on the expansion tank filler. Note: At this point, all air should be out of the system. However, the system must be purged while the burner is operating to remove water and steam. Instructions are given later for purging water. HC heaters filling fluid circuits with thermal fluid This procedure applies to HC heaters with auxiliary (side) pumps. Side pumps circulate thermal fluid in thermal fluid circuits that can be operated independently. Using this procedure you first fill the heater coil circuit and then each independent circuit, one at a time. The procedure assumes the use of a transfer pump to pump the thermal fluid from its shipping containers into the expansion tank of the heater. Consequently, after all Page 6

7 thermal fluid circuits have been filled, any excess fluid in the expansion tank can be pumped back into the containers. If you don t have a transfer pump you must take extra care not to overfill the system. Otherwise, you may have difficulty removing excess fluid from the expansion tank. This procedure can take 2 hours or longer, depending on the size of the circuits. 1. Set the power disconnect switch (the handle) on the control panel (Fig. 3) to ON. 2. Set valves as indicated in Fig. 10 for purge. 3. Make sure all valves at the auxiliary pumps are closed. 4. Make sure drain valve (Fig. 8) is closed. 5. Remove the cap from the expansion tank filler (B, Fig. 5). Pump thermal fluid from the shipping containers into the expansion tank until the tank is full. Leave the cap off of the expansion tank filler. Excess air will exit through this opening as you circulate fluid. 6. Momentarily set switch marked CIRCULATING PUMP to ON and check the circulating pump motor for proper rotation as marked on pump housing. 7. Set the switch labeled CIRCULATING PUMP to ON (Fig. 4). The circulating pump (P, Fig. 5) should begin to operate. The pump may cavitate intermittently as trapped air escapes from the system. Cavitation can be recognized by a rattling sound. Another indication of cavitation is oscillation of the pressure gauge at the inlet of the coil (Fig. 6). Note: If the cavitation continues, check the pressure gauge at the inlet of the coil. If the gauge indicates a continuing drop in pressure, the strainer may be clogged. In that case, shut off the circulating pump and clean the strainer. You may have to clean the strainer several times during start-up. 8. Observe fluid level in the sight gauge. When its level drops to about 3 inches, set the switch labeled CIRCULATING PUMP to OFF (Fig. 4). This is a precaution to avoid drawing air into the system. 9. Repeat the previous steps of filling the tank and operating the circulation pump until the coil circuit is full. You will know the circuit is full when the level in the sight gauge does not drop when the circulation pump is operated. 10. the valve at auxiliary pump #1. Make sure that all valves in the circuit connected to this pump are open. 11 Momentarily set switch marked AUXILIARY PUMP #1 to ON and check auxiliary pump motor for proper rotation as marked on pump housing. Page While the circulation pump is operating, set the switch labeled AUXILIARY PUMP #1 to ON (Fig. 4). Auxiliary pump #1 at the manifold should begin to operate. The auxiliary pump may cavitate, producing the same rattling sound mentioned earlier. This may continue intermittently throughout the fill procedure. If cavitation does not stop after a few seconds, momentarily close and open the valve at the outlet of auxiliary pump #1 until cavitation stops and pressure at the outlet of the pump stabilizes. 13. Observe fluid level in the sight gauge. If fluid level drops to about 3 inches, set the switches labeled CIRCULATING PUMP and AUXILIARY PUMP #1 to OFF (Fig. 4). 14. Repeat the cycle of filling the expansion tank and operating both the circulation pump and the auxiliary pump until the circuit is full. You will know the circuit is full when the level in the sight gauge does not drop when the two pumps are operated. 15. If you have additional auxiliary pumps, repeat steps 10 through 13 above for each additional auxiliary pump. 16. When all ciruits are full make sure the fluid level in the expansion tank is 3 to 4 inches as indicated on the sight gauge. This is the normal cold fluid level. If the level is higher than 3 to 4 inches, pump excess fluid out of the tank back into the original containers. 17. Replace cap on the expansion tank filler. Note: At this point, all air should be out of the system. However, the system must be purged while the burner is operating to remove water and steam. Instructions are given later for purging water. Checking differential pressure switch The differential pressure switch (Fig. 6) should be checked after the system has been filled with thermal fluid and water has been purged from the system. A separate Tec-Note provides instructions for checking the switch. Purging water from the system This procedure requires firing the burner and heating the thermal fluid. WARNING! Beware of hot parts. Do not touch uninsulated thermal fluid valves, piping, etc. with bare hands when the heater is in operation. Their surfaces exceed 300 degrees F (140 degrees C and can cause severe burns resulting in serious injury or death. Wear chemical and heat gloves when you must work on hot parts or drain hot fluid from the heater. The burner has been factory tested. Factory settings should be adequate for all operations covered in this procedure.

8 However, burner tuning can be affected by local altitude or other atmospheric conditions and should be re-tuned after initial operation. See Tec-Note entitled How to recognize an out-of-tune burner. Only a thoroughly qualified burner technician should re-tune the burner. At some point after step 12 of this purge procedure you should check limit circuit devices for proper operation. Instructions for checking limit devices are provided in a separate Tec-Note. NOTICE: Never leave the heater unattended while the burner is in operation until after you check the limit devices. Note: 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 moisture in the thermal fluid. 1. Set the power disconnect switch (the handle) on the control panel (Fig. 3) to ON. 2. Make sure the BURNER MODULATION CONTROLLER and the MEDIA HIGH TEMPERATURE CONTROLLER are set per previous instructions. 3. Make sure thermal fluid circuits are filled per previous instructions. Thermal fluid level should be 3 inches in the sight gauge (Fig. 7.) 4. Make sure drain valve (Fig. 8) is closed. 5. Make sure valves are set as indicated in Fig. 10 for purge. 6. For HC heater, make sure the auxiliary valves on the manifold are open. 7. Set the switch labeled FUEL SELECTOR (Fig. 4), to either OIL or GAS, depending on the fuel you are using. For GAS: the main gas manual shutoff valve (Fig. 9). the secondary gas manual shutoff valve (Fig. 9). the pilot gas manual shutoff valve (Fig. 9). Make sure fuel oil supply valve (not furnished with heater) is shut off. For OIL: fuel oil supply valve (not furnished with heater). the pilot gas manual shutoff valve (Fig. 9). Make sure the main gas manual shutoff valve (Fig. 9) is closed. Make sure the secondary gas manual shutoff valve (Fig. 9) is closed. 8. Set the switch labeled CIRCULATING PUMP to ON (Fig. 4). 9. For HC heaters, set all switches labeled AUXILIARY PUMP to ON. 10. Set the BURNER MODULATION CONTROLLER (Fig. 4) to manual. The message MAN should appear in the upper portion of the display. A green light next to OUT should appear in the lower portion of the display. Adjust the burner output to 0 percent. You may have to increase output (using the up arrow key) to achieve enough heat to reach the desired set point of 230 degrees F. Likewise, as you increase the set point in the following steps, you may need to increase the output. Increase the output in increments of about 10 percent. 11. Momentarily set the switch labeled BURNER to ON (Fig. 4). and make sure rotation of blower motor is in the direction marked on the motor. 12. Set the switch labeled BURNER to ON (Fig. 4). After about 2 minutes the Fireye BURNER DISPLAY should show the message AUTO FLAME SIGNAL. This indicates that the burner has ignited properly. 13. Observe the BURNER MODULATION CONTROLLER (Fig. 4.) The temperature of the thermal fluid should rise to the set point of 230 degrees F. Water and steam will exit the overflow pipe. Operate the heater at this temperature until no water or steam exits the overflow pipe. Note: This can take from 45 minutes to several hours, depending on the amount of moisture in the system. 14. On the MEDIA HIGH TEMPERATURE CONTROLLER, reset the set point to 290 degrees F. 15. On the BURNER MODULATION CONTROLLER, reset the set point to 240 degrees F. Observe the BURNER MODULATION CONTROLLER. The temperature of the thermal fluid should rise to its new set point of 240 degrees F. Operate the heater at this temperature until no water or steam exits the overflow pipe. This can take from 45 minutes to several hours. 16. On the MEDIA HIGH TEMPERATURE CONTROLLER, reset the set point to 300 degrees F. 17. Reset the BURNER MODULATION CONTROLLER to 250 degrees F. Operate the heater until no steam or water exits the overflow pipe. 18. Continue this cycle of raising the set point on the MEDIA HIGH TEMPERATURE CONTROLLER and the BURNER MODULATION CONTROLLER in increments of 10 degrees. Each time you raise the set point, operate the heater until no steam or water exits the overflow pipe. Continue this cycle until you reach the set point of 320 degrees F on the BURNER MODULATION CONTROLLER. Note: 320 degrees F is a typical set point for heater operation at an asphalt plant. The desired set point at your facility may be higher. Page 8

9 Note: if you attempt to save time by increasing the temperatures in increments larger than 10 degrees there is a risk of boiling over the expansion tank. Likewise, if you do not wait until all steam has exited the overflow pipe, there is also risk of boiling over the expansion tank. 19. Adjust the set point on the MEDIA HIGH TEMPERATURE CONTROLLER (Fig. 4.) See Fig. 11 for suggested settings. Note that the desired settings at your facility may differ from those shown. 20. Set the BURNER MODULATION CONTROLLER (Fig. 4) to auto. 21. Set valves as indicated in Fig. 10 for Run. 22. Reset the pressure differential switches according to separate Tec-Note on setting Barksdale pressure switch. Shutting down the heater 1. While the heater is in low fire set the switch marked BURNER to OFF (Fig. 4). 2. Allow the circulation pump and the auxiliary pumps (HC heater only) to continue operating for approximately 10 minutes. 3. Set the switch marked CIRCULATING PUMP to OFF (Fig. 4). 4. For HC heaters, set all switches marked AUXILIARY PUMP to OFF. 5. Make sure these valves are closed: Main gas manual shutoff valve ( Fig. 9). Secondary gas manual shutoff valve (Fig. 9). Pilot gas manual shutoff valve (Fig. 9). Close valve in the fuel oil supply line to heater. 6 Set the power disconnect switch (the handle) on the control panel (Fig. 3) to OFF. Checking pump alignment again Immediately after operation of the heater for the first time and before the system has cooled down, check pump alignment again in accordance with instructions published by the pump manufacturer. Starting heater for routine operation Follow steps 1 through 9 of the procedure for purging water from the system. Flame scanner precaution The flame scanner and amplifier used on HC and HCS heaters are the non-self checking types. However, the flame monitor checks the flame scanner each time the heater is started. Consequently, it is extremely important that the heater cycles off and on a minimum of once every 12 hours. If the heating system is highly stable (as it should be), the heater may not automatically cycle off and on that often. Therefore, to ensure that the flame scanner is okay, you should manually switch the heater off for a second or two and then back on. Do this once each morning and once again late in the day. In the event that the flame scanner fails while the heater is operating, it may not shut the heater down. Thus, the scanner could allow the fuel valves to remain open, even if there is an inadvertent loss of flame. This would allow the heater and surrounding area to become saturated with unlit fuel, creating an extremely unsafe condition. If you try to restart a heater that has a defective flame scanner, the heater will not restart. Instead, the flame monitor will show the message FALSE FLAME. This most likely indicates that the flame scanner is bad and should be replaced. Although a defective amplifier, programmer or chassis can also cause a false flame indication, a defective flame scanner is usually the problem. Never disconnect and reconnect the flame scanner or take any other action to circumvent the scanner in order to restart the heater. Instead, replace the component. Otherwise, you could create an unsafe condition as described above. WARNING! To ensure that the flame scanner is working properly, manually restart the heater twice daily. If the scanner is defective and not working properly it will prevent a restart and should be replaced. Never disconnect the scanner temporarily in order to restart the heater. That would prevent if from shutting off fuel in case of a flame failure. This could cause an explosion and fire, causing injury or death. Heatec, Inc Wilson Road Chattanooga, Tennessee (423) (800) Fax (423) Heatec, Inc. Page 9