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 Kentwood, MI, the failures cluster at predictable points: an oxide-coated flame sensor, 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.
When the AC quits in summer, see AC Repair.
Warning Signs for Furnace Repair
Recognizing the warning signs early can save you time and money. Here are the most common indicators that it's time to call a professional:
- A pilot or burner flame that is lazy yellow instead of crisp blue
- Booming or banging at light-off from delayed ignition
- A furnace that shuts off every few minutes before the house warms up
- The igniter glows and clicks, yet no flame ever appears
- Squeals, scrapes, or grinding noises behind the blower door
- Repeated shutdowns just seconds after the burners light
- Water, rust stains, or black soot around the flue or cabinet
- A fan that keeps running while the registers blow cool air
Early Action Saves Money
What seems like a minor issue today can take out a compressor or heat exchanger tomorrow. Don't wait, call (616) 207-6437 and we'll take a look right away.
