From the hallway, a furnace that will not heat looks the same no matter what broke. Inside the cabinet, though, everything happens in a strict order: inducer on, pressure switch closed, igniter glowing, gas valve open, burners lit, flame proven, and finally the blower sending heat through the house. Diagnosis is mostly a matter of finding where that chain breaks. In Wauwatosa homes, it tends to be the same handful of culprits: a flame sensor coated in oxide, a hot surface igniter cracked by thermal cycling, a pressure switch held open by a tired inducer or a plugged condensate trap, or a control board with a burned relay.
When the AC quits in summer, see AC Repair.
When to Call for Furnace Repair in Wauwatosa
Catching these issues early helps you avoid costly problems. Keep an eye out for the following clues:
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- A furnace that shuts off every few minutes before the house warms up
- Yellow, wavering burner flames where they should be sharp blue
- Burners light, run a few seconds, then shut down repeatedly
- Squeals, scrapes, or grinding noises behind the blower door
- A bang or boom when the burners ignite late
- The furnace clicks and glows but the burners never light
- A fan that keeps running while the registers blow cool air
Early Action Saves Money
Most HVAC failures start small, a weak capacitor, a squealing blower, a system that runs a little longer each week. If you notice any of these signs, call (414) 432-5103 for a prompt inspection.
