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 Ann Arbor, MI, 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.
Signs You Need Furnace Repair in Ann Arbor
Spotting the early warning signs lets you act before the problem gets expensive. These are the signals our technicians see most often:
- Air moving through the vents that never gets warm
- Grinding or high-pitched squeals from the blower
- Loud booms at startup caused by delayed ignition
- A flame that burns soft and yellow rather than steady blue
- A furnace that shuts off every few minutes before the house warms up
- Burners light, run a few seconds, then shut down repeatedly
- The furnace clicks and glows but the burners never light
- Rust streaks, soot, or water around the cabinet or flue
Don't Wait for a Total Failure
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. Call (734) 215-6957 at the first sign of trouble.
