Lennox furnace error code 77

Being merciful towards the technical issues that often deal with electronics, in-depth information on error codes is not provided here. What is given here is only the description of what to do when the said error code appears. First of all, make sure that you know your model number and serial number so as not to be suspicious of other Lennox products that you may have installed in your house.

If by chance, these two pieces necessarily from different sources are identical, then one does not need a rigid step-by-step procedure for getting into check what has caused the infamous error code 77 – because it would certainly be due to a warranty label or just settling for grounding wiring design.

According to the Lennox repair guide, when the fan has not been operating for the last 36 hours, this implies that a furnace error code 77 may have occurred.

Lennox’s high-efficiency furnace comes with a self-diagnostic system. Regular upkeep and airflow checks allow this furnace to run smoothly, producing heat and hot water at the desired temperature. The furnaces can be manually checked via the touch control panel or with the self-diagnostic options on the customer’s Lennox online account.

The given error code, 77, typically represents a problem with the combustion control module. That is the low-voltage power supply input to the assembly.

The Lennox furnace error code can seem perplexing and hard to decipher, but it is actually not that complicated.

If you see the error code 77, then you know to check the outdoor sensor. You might want to consider replacing the sensor if this was your first trip when you noticed this error code.

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