Every time your thermostat calls for heat, the furnace works through a fixed checklist. The inducer motor starts and proves draft by closing a pressure switch, the hot surface igniter heats up, the gas valve opens, the burners light, and the flame sensor confirms there is fire. Only after all of that does the blower start pushing warm air into the house. Finding the step that fails is most of the job. Around Morristown, TN, the usual failure points are an oxide-coated flame sensor, an igniter cracked by years of heating and cooling, a pressure switch that stays open because of a weak inducer or a clogged condensate trap on a high-efficiency unit, and control boards with burned relays. Each one halts the startup, and from the hallway they all look alike.
When the AC quits in summer, see AC Repair.
Signs You Need Furnace Repair in Morristown
Spotting the early warning signs lets you act before the problem gets expensive. Here are the most common indicators that it's time to call a professional:
- Short cycling every few minutes without reaching the setpoint
- Squealing or grinding from the blower compartment
- Burners light, run a few seconds, then shut down repeatedly
- A fan that keeps running while the registers blow cool air
- The igniter glows and clicks, yet no flame ever appears
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- Yellow, wavering burner flames where they should be sharp blue
- Loud booms at startup caused by delayed ignition
Early Action Saves Money
Left unchecked, even a small fault or temperature swing often signals a system working its way toward a breakdown. If you notice any of these signs, call (423) 205-3316 for a prompt inspection.
