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 Tulsa, OK, the usual failure points are a flame sensor fouled with oxide, 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
The sooner you notice these red flags, the easier and cheaper the fix. Keep an eye out for the following clues:
- Rust streaks, soot, or water around the cabinet or flue
- Yellow, wavering burner flames where they should be sharp blue
- Loud booms at startup caused by delayed ignition
- A fan that keeps running while the registers blow cool air
- Repeated shutdowns just seconds after the burners light
- The igniter glows and clicks, yet no flame ever appears
- Grinding or high-pitched squeals from the blower
- Short cycling every few minutes without reaching the setpoint
Early Action Saves Money
Most HVAC failures start small, a weak capacitor, a squealing blower, a system that runs a little longer each week. If you notice any of these signs, call (918) 301-0260 for a prompt inspection.
