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 Johns Creek, GA, 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.
Cooling trouble instead? See AC Repair.
Warning Signs for Furnace Repair
Spotting the early warning signs lets you act before the problem gets expensive. Watch for these telltale signs:
- Clicking and a glowing igniter with no burner flame
- Grinding or high-pitched squeals from the blower
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- Repeated shutdowns just seconds after the burners light
- Loud booms at startup caused by delayed ignition
- Frequent on-off cycling that never reaches the thermostat setting
- The blower runs constantly but the air never warms
- A pilot or burner flame that is lazy yellow instead of crisp blue
Early Action Saves Money
Most HVAC failures start small, a weak capacitor, a squealing blower, a system that runs a little longer each week. Call (470) 200-3164 at the first sign of trouble.
