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 Alexandria, VA, 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.
When the AC quits in summer, see AC Repair.
When to Call for Furnace Repair in Alexandria
The sooner you notice these red flags, the easier and cheaper the fix. Keep an eye out for the following clues:
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- Squealing or grinding from the blower compartment
- A pilot or burner flame that is lazy yellow instead of crisp blue
- Frequent on-off cycling that never reaches the thermostat setting
- A bang or boom when the burners ignite late
- Burners light, run a few seconds, then shut down repeatedly
- Air moving through the vents that never gets warm
- Clicking and a glowing igniter with no burner flame
Act Before It Gets Worse
Most HVAC failures start small, a weak capacitor, a squealing blower, a system that runs a little longer each week. Call (571) 741-3096 at the first sign of trouble.
