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 Bowie 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
Recognizing the warning signs early can save you time and money. Watch for these telltale signs:
- Repeated shutdowns just seconds after the burners light
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- Grinding or high-pitched squeals from the blower
- Clicking and a glowing igniter with no burner flame
- Air moving through the vents that never gets warm
- Frequent on-off cycling that never reaches the thermostat setting
- Booming or banging at light-off from delayed ignition
- 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. If you notice any of these signs, call (240) 896-8301 for a prompt inspection.
