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. Most of the diagnosis comes down to finding the broken link. In Racine 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.
Warning Signs for Furnace Repair
The sooner you notice these red flags, the easier and cheaper the fix. Here are the most common indicators that it's time to call a professional:
- Flames that start, last a few seconds, and go out again and again
- Rust streaks, soot, or water around the cabinet or flue
- Loud booms at startup caused by delayed ignition
- A fan that keeps running while the registers blow cool air
- Squeals, scrapes, or grinding noises behind the blower door
- A furnace that shuts off every few minutes before the house warms up
- The furnace clicks and glows but the burners never light
- A flame that burns soft and yellow rather than steady blue
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 (262) 401-5033 at the first sign of trouble.
