Every time your thermostat calls for heat, the furnace runs 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 Charleston, SC, 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. Any one of them halts the startup, and from the hallway they all look alike.
For air conditioning breakdowns, see AC Repair.
When to Call for Furnace Repair in Charleston
Spotting the early warning signs lets you act before the problem gets expensive. Watch for these telltale signs:
- Water, rust stains, or black soot around the flue or cabinet
- The furnace clicks and glows but the burners never light
- A bang or boom when the burners ignite late
- The blower runs constantly but the air never warms
- Flames that start, last a few seconds, and go out again and again
- Grinding or high-pitched squeals from the blower
- A furnace that shuts off every few minutes before the house warms up
- A pilot or burner flame that is lazy yellow instead of crisp blue
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 (843) 268-6960 for a prompt inspection.
