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. Diagnosis is mostly a matter of finding where that chain breaks. In Austin 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
Catching these issues early helps you avoid costly problems. Here are the most common indicators that it's time to call a professional:
- A bang or boom when the burners ignite late
- Water, rust stains, or black soot around the flue or cabinet
- Yellow, wavering burner flames where they should be sharp blue
- The furnace clicks and glows but the burners never light
- Frequent on-off cycling that never reaches the thermostat setting
- Flames that start, last a few seconds, and go out again and again
- Grinding or high-pitched squeals from the blower
- The blower runs constantly but the air never warms
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. Don't wait, call (737) 344-9531 and we'll take a look right away.
