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 Nashua, NH, 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. Each one halts the startup, and from the hallway they all look alike.
Cooling trouble instead? See AC Repair.
Signs You Need Furnace Repair in Nashua
Catching these issues early helps you avoid costly problems. Keep an eye out for the following clues:
- Water, rust stains, or black soot around the flue or cabinet
- The blower runs constantly but the air never warms
- Grinding or high-pitched squeals from the blower
- A flame that burns soft and yellow rather than steady blue
- Burners light, run a few seconds, then shut down repeatedly
- Frequent on-off cycling that never reaches the thermostat setting
- A bang or boom when the burners ignite late
- The igniter glows and clicks, yet no flame ever appears
Don't Wait for a Total Failure
Left unchecked, even a small fault or temperature swing often signals a system working its way toward a breakdown. Call (351) 345-9275 at the first sign of trouble.
