Troubleshooting: Heating Sequence of Operation (Continued)
| HEATING SEQUENCE OF OPERATION |
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CONTINUED |
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| SEE BOX A |
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| NORMAL OPERATION. |
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| SEE BOX B |
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| THERMOSTAT CALLS FOR HEAT. |
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| RETURN TO FIRST−STAGE HEAT MODE. |
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| FIRST−STAGE CONTINUES UNTIL SECOND− |
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SECOND−STAGE (HIGH FIRE) HEAT | NO | STAGE PRESSURE SWITCH CAN BE PROVEN | YES | ||||
or HEAT DEMAND IS SATISFIED. A FIVE (5) | |||||||
PRESSURE SWITCH CLOSED? |
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| MINUTE WAIT PERIOD IS INITIATED BEFORE |
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YES |
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| RETRY. WERE 5 ATTEMPTS MADE FOR |
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| SECOND−STAGE HEAT? |
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HEAT DEMAND SATISFIED? |
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| NO |
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STATUS LED −− HEARTBEAT. |
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| SEE BOX C |
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| FIRST−STAGE HEAT DEMAND SATISFIED? |
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YES | YES |
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SINGLE−STAGE THERMOSTAT MODE | TWO STAGE THERMOSTAT MODE? |
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(DIP SWITCH SET AT |
| (DIP SWITCH SET AT |
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YES |
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| YES |
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| FIRST AND SECOND STAGE HEAT |
| SECOND STAGE HEAT | |||
GAS VALVE OFF, COMBUSTION AIR | YES | NO | DEMAND SATISFIED? | ||||
INDUCER OFF AFTER 5−SECOND | DEMAND SATISFIED SIMULTANEOUSLY. | STATUS LED −− HEARTBEAT. | |||||
LOW SPEED POST PURGE PERIOD, |
| STATUS LED −− HEARTBEAT. |
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INDOOR BLOWER OFF DELAY |
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INITIATED ON LOW HEAT SPEED. |
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| YES |
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STATUS LED −− HEARTBEAT. |
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| GAS VALVE, COMBUSTION AIR INDUCER | ||||
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| AND INDOOR BLOWER RETURN TO FIRST− | ||||
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| STAGE OPERATION. |
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| STATUS LED −− HEARTBEAT. |
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| FIRST STAGE HEAT DEMAND SATISFIED? | ||||
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| YES |
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DEMAND FOR HEAT SATISFIED. |
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| GAS VALVE OFF. COMBUSTION AIR INDUCER | ||||
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| OFF AFTER 5−SECOND LOW SPEED POST− | |||||
POWER ON STAND BY. |
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| PURGE PERIOD. INDOOR BLOWER OFF. | |||||
STATUS LED −− PULSE. |
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| DELAY INITIATED ON LOW HEAT SPEED. | |||||
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| STATUS LED −− PULSE. |
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