A modern furnace runs a strict startup sequence, and knowing where the sequence breaks is most of the diagnosis. The thermostat calls, the inducer motor spins up to prove draft through a pressure switch, the hot surface igniter glows, the gas valve opens, the burners light, the flame sensor confirms fire, and only then does the blower deliver heat to the house. In Athens, GA, the failures cluster at predictable points: a flame sensor coated in oxide that can no longer prove the flame, a hot surface igniter cracked from years of thermal cycling, a pressure switch that will not close because the inducer is weak or the condensate trap on a high-efficiency model has clogged, or a control board with a burned relay. Each one stops the sequence cold, and each one mimics the others from the hallway.
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. These are the signals our technicians see most often:
- Short cycling every few minutes without reaching the setpoint
- The blower runs constantly but the air never warms
- Booming or banging at light-off from delayed ignition
- Water, rust stains, or black soot around the flue or cabinet
- Squealing or grinding from the blower compartment
- Repeated shutdowns just seconds after the burners light
- Clicking and a glowing igniter with no burner flame
- A flame that burns soft and yellow rather than steady 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 (706) 203-3429 for a prompt inspection.
