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Lennox Service Manuals & Error Codes
202Service Manuals
400Error Codes
5Appliance Types
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Top Error Codes for Lennox
CodeTypeDescription
1Air ConditionerPower loss for two electrical cycles (33-40 milliseconds), suggesting dirty or...10Air ConditionerOption 2 safety device switch opens.11Air ConditionerCompressor temperature sensor wires have shorted together.14Air ConditionerControl is in TEST mode; does not indicate a problem.15Air ConditionerMode jumper is not in place on the TSC5 two-speed control.2Air ConditionerInput indication - acknowledges a change such as jumper setting changes, delay...3Air ConditionerUnsteady thermostat input - intermittent inputs from the room thermostat, most...4Air ConditionerPressure switch opens after compressor has run for less than two minutes, may...5Air ConditionerPressure switch opens after compressor has run for more than two minutes, may...6Air ConditionerCompressor temperature exceeded its limit after running less than five minutes...7Air ConditionerCompressor temperature exceeded its limit after running more than five minutes...8Air ConditionerOption 1 safety device switch opens after compressor runs less than five...9Air ConditionerOption 1 safety device switch opens after compressor runs more than five...E105Air ConditionerThe outdoor control has lost communication with either the thermostat or indoor...E120Air ConditionerThere is a delay in the outdoor unit responding to the system.