From the hallway, a furnace that will not heat looks the same no matter what broke. Inside the cabinet, though, the sequence is strict: inducer on, pressure switch closed, igniter glowing, gas valve open, burners lit, flame proven, and finally the blower moving heat through the ducts. Most of the diagnosis comes down to finding the broken link. In Saginaw 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.
Cooling trouble instead? See AC Repair.
Warning Signs for Furnace Repair
Spotting the early warning signs lets you act before the problem gets expensive. These are the signals our technicians see most often:
- The blower runs constantly but the air never warms
- The furnace clicks and glows but the burners never light
- A bang or boom when the burners ignite late
- Repeated shutdowns just seconds after the burners light
- A flame that burns soft and yellow rather than steady blue
- Frequent on-off cycling that never reaches the thermostat setting
- Water, rust stains, or black soot around the flue or cabinet
- Squeals, scrapes, or grinding noises behind the blower door
Early Action Saves Money
What seems like a minor issue today can take out a compressor or heat exchanger tomorrow. If you notice any of these signs, call (989) 203-1135 for a prompt inspection.
