START
TROUBLESHOOTING GUIDE
10
Is red LED status light on?
YES
Is red LED status light blinking rapidly without a pause?
NO
Is red LED status light blinking ON/OFF slowly with a combination of short and long flashes?
YES
Determine status code. The status code is a 2 digit number with the first digit determined by the number of short flashes and the second digit by the number of long flashes.
Once status code is determined, the control will go through a brief component test sequence by operating inducer motor, HSI, blower motor relay heat speed, and cool speed for approximately
NO
YES
NO
Is there 115v at L1 and L2? | NO | |||
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| YES |
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| NO | ||
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Is there 24v at | ||||
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| YES |
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Replace control board. |
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Check for correct line voltage polarity. If units are twinned, check for proper
Check for previous fault by momentarily shorting the TEST terminal and the "C" terminal until the LED goes out. LED will flash the status code of any previous fault or the code 11 (ONE
SHORT AND ONE LONG FLASH) if no previous fault. After the control repeats the code 3 times, it will sequentially operate inducer motor, HSI, blower motor relay heat speed, and cool speed for approximately 10 - 15 sec, then go off.
Was there a previous fault code | NO |
other than No. 11?
YES
Is door switch closed?
YES
Is there 115v going to switch?
YES
Replace door switch.
Replace transformer.
Run system through a heating or cooling cycle to check operation. Status codes are erased after 48 hrs or whenever power (115v or 24v) is interrupted.
NO
NO
Close door switch and go to start.
Is circuit breaker closed? | NO |
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Close circuit breaker and go back to start.
YES
Check for continuity in wire from circuit breaker to furnace.
Go to section with status code determined.
