Furnace Flame Sensor Cleaning & Replacement

Professional Furnace Flame Sensor Cleaning & Replacement in Asheville & Western NC

A Small Component With an Outsized Impact

The flame sensor is a slender metal rod that sits directly in the burner flame. Its sole purpose is to confirm that the burners have actually ignited. If the sensor fails to detect flame within seconds of gas flow, the control board cuts the gas valve for safety. Over time, oxidation and combustion residue coat the sensor surface, preventing it from reading the flame correctly. The result: your furnace lights, runs for a handful of seconds, shuts down, and restarts in a maddening cycle. This short-cycling complaint is one of the most frequent heating calls we receive from WNC homeowners.

A Quick Clean or a Simple Swap

Often, gently cleaning the rod with fine abrasive material restores full sensor function — a 15-minute repair. If the rod is cracked, warped, or cleaning fails to resolve the problem, replacement is easy and inexpensive. Either way, this is among the fastest furnace repairs we handle.

We Verify, Not Just Hope

Flame sensor symptoms overlap with other issues — a failing gas valve, a cracked ignitor, or a faulty control board can produce similar behavior. Our technicians measure the sensor's microamp output, test the gas valve, and confirm the furnace cycles correctly before calling the job complete.