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 begin sending warm air into the house. Finding the step that fails is most of the job. Around Harlingen, TX, 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.
For air conditioning breakdowns, see AC Repair.
Warning Signs for Furnace Repair
Recognizing the warning signs early can save you time and money. Keep an eye out for the following clues:
- Air moving through the vents that never gets warm
- Yellow, wavering burner flames where they should be sharp blue
- Rust streaks, soot, or water around the cabinet or flue
- Clicking and a glowing igniter with no burner flame
- Loud booms at startup caused by delayed ignition
- Squealing or grinding from the blower compartment
- A furnace that shuts off every few minutes before the house warms up
- Burners light, run a few seconds, then shut down repeatedly
Early Action Saves Money
Left unchecked, even a small fault or temperature swing often signals a system working its way toward a breakdown. Call (956) 247-0469 at the first sign of trouble.
