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 Middletown, CT, 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
Recognizing the warning signs early can save you time and money. These are the signals our technicians see most often:
- Burners light, run a few seconds, then shut down repeatedly
- Yellow, wavering burner flames where they should be sharp blue
- Short cycling every few minutes without reaching the setpoint
- Rust streaks, soot, or water around the cabinet or flue
- The furnace clicks and glows but the burners never light
- Air moving through the vents that never gets warm
- Squeals, scrapes, or grinding noises behind the blower door
- Loud booms at startup caused by delayed ignition
Early Action Saves Money
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. At the first hint of a problem, call (860) 470-9962 for a fast inspection.
