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Error code reference
Lennox Heat Pump Error Codes
55 error codes documented with diagnostic procedures.
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1Long Run Time-Compressor is running extremely long run cycles, indicating possible low…10Option 2 safety device switch opens.11Compressor temperature sensor wires have shorted together.12Problem with the operation of the outdoor temperature sensor.14Control is in TEST mode; does not indicate a problem.15Mode jumper is not in place on the TSC-6 control.2Input indication acknowledging a change (jumper setting changes, delay overrides, or…3Unsteady thermostat input indicating intermittent inputs from the room thermostat, most…4Low or high pressure switch opens after compressor has run for less than two minutes, may…5Low or high pressure switch opens after compressor has run for more than two minutes, may…6Compressor temperature exceeded its limit after running less than five minutes (or open…7Compressor temperature exceeded its limit after running more than five minutes (or open…8Welded Contactor-Compressor always runs; contactor failed to open or thermostat demand…9Option 1 safety device switch opens after compressor runs more than five minutes.Alternating FAST FlashCoil sensor problemAlternating FAST Flash (Green/Red)Coil sensor problemAlternating SLOW Flash5-minute anti-short cycle delay (initial power up, safety trip, or end of room thermostat…Alternating SLOW Flash (Green/Red)5-minute anti-short cycle delay after initial power up, safety trip, or end of room…DS2 Alternating FAST Flash / DS1 Alternating FAST FlashCoil sensor problemDS2 Alternating SLOW Flash / DS1 Alternating SLOW Flash5-minute anti-short cycle delay due to initial power up, safety trip, or end of room…DS2 OFF / DS1 OFFNo power (24V) to control terminals R & C or board failure.DS2 OFF / DS1 ONLow pressure lockoutDS2 OFF / DS1 SLOW FlashLow pressure faultDS2 ON / DS1 OFFHigh pressure lockoutDS2 ON / DS1 ONCircuit board failureDS2 Simultaneous FAST Flash / DS1 Simultaneous FAST FlashAmbient sensor problemDS2 Simultaneous SLOW Flash / DS1 Simultaneous SLOW FlashNormal operationDS2 SLOW Flash / DS1 OFFHigh Pressure FaultDS2:Alternating FAST Flash / DS1:Alternating FAST FlashCoil sensor problemDS2:Alternating SLOW Flash / DS1:Alternating SLOW Flash5-minute anti-short cycle delay due to initial power up, safety trip, or end of room…DS2:FAST Flash / DS1:OFFDischarge sensor lockoutDS2:FAST Flash / DS1:ONDischarge line temperature lockoutDS2:OFF / DS1:FAST FlashDischarge sensor faultDS2:OFF / DS1:OFFNo power (24V) to board terminals R & C or board failure.DS2:OFF / DS1:ONLow pressure lockoutDS2:OFF / DS1:SLOW FlashLow pressure faultDS2:ON / DS1:OFFHigh pressure lockoutDS2:ON / DS1:ONCircuit board failureDS2:Simultaneous FAST Flash / DS1:Simultaneous FAST FlashAmbient sensor problemDS2:Simultaneous SLOW Flash / DS1:Simultaneous SLOW FlashNormal operationDS2:SLOW Flash / DS1:OFFHigh pressure faultDS2:SLOW Flash / DS1:ONDischarge line temperature faultGreen FAST Flash / Red OFFDischarge sensor lockout (5 strikes)Green FAST Flash / Red ONDischarge line temperature lockout (5 strikes)Green OFF / Red FAST FlashDischarge sensor faultGreen OFF / Red SLOW FlashLow pressure faultGreen ON / Red OFFHigh pressure lockout (5 strikes)Green ON / Red ONCircuit board failureGreen SLOW Flash / Red OFFHigh pressure faultGreen SLOW Flash / Red ONDischarge line temperature faultOFF/OFFNo power (24V) to board terminals R & C or board failure.Simultaneous FAST FlashAmbient sensor problemSimultaneous FAST Flash (Green/Red)Ambient sensor problemSimultaneous SLOW FlashNormal operationSimultaneous SLOW Flash (Green/Red)Normal operation
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