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 sending heat through the house. Diagnosis is mostly a matter of finding where that chain breaks. In Murfreesboro 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
Spotting the early warning signs lets you act before the problem gets expensive. Watch for these telltale signs:
- Repeated shutdowns just seconds after the burners light
- The blower runs constantly but the air never warms
- Booming or banging at light-off from delayed ignition
- Yellow, wavering burner flames where they should be sharp blue
- Squeals, scrapes, or grinding noises behind the blower door
- The igniter glows and clicks, yet no flame ever appears
- Short cycling every few minutes without reaching the setpoint
- Soot, rust, or moisture near the furnace cabinet or vent pipe
Act Before It Gets Worse
A failing capacitor, clogged condensate drain, or dirty flame sensor rarely fixes itself and usually gets more expensive to address the longer it runs. At the first hint of a problem, call (615) 537-0355 for a fast inspection.
