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 Anaheim, CA, 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. Any one of them 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 Anaheim
Recognizing the warning signs early can save you time and money. Keep an eye out for the following clues:
- Loud booms at startup caused by delayed ignition
- Yellow, wavering burner flames where they should be sharp blue
- Grinding or high-pitched squeals from the blower
- The furnace clicks and glows but the burners never light
- Frequent on-off cycling that never reaches the thermostat setting
- A fan that keeps running while the registers blow cool air
- Water, rust stains, or black soot around the flue or cabinet
- Burners light, run a few seconds, then shut down repeatedly
Don't Wait for a Total Failure
What seems like a minor issue today can take out a compressor or heat exchanger tomorrow. If you notice any of these signs, call (714) 646-1684 for a prompt inspection.
