Dirty flame sensors interrupting furnace operation during cold spells
Why it happens here
Long winter run times can reveal buildup on a flame sensor, especially when routine maintenance has been missed. The furnace may ignite and then shut down because the control cannot confirm a stable flame. Repeated restarts leave Fairmount rooms cold and can confuse the problem with a larger ignition failure.
Our approach
We inspect the ignition sequence and verify sensor response rather than replacing parts by assumption. If cleaning restores reliable flame sensing, we test several heating cycles. If the sensor or wiring has failed, we explain the replacement and confirm safe operation afterward.