Every time your thermostat calls for heat, the furnace runs a fixed checklist. The inducer motor starts and proves draft by closing a pressure switch, the hot surface igniter heats up, the gas valve opens, the burners light, and the flame sensor confirms there is fire. Only after all of that does the blower begin sending warm air into the house. Finding the step that fails is most of the job. Around Dallas, TX, the usual failure points are a flame sensor fouled with oxide, an igniter cracked by years of heating and cooling, a pressure switch that stays open because of a weak inducer or a clogged condensate trap on a high-efficiency unit, and control boards with burned relays. Each one halts the startup, and from the hallway they all look alike.
When the AC quits in summer, see AC Repair.
When to Call for Furnace Repair in Dallas
Recognizing the warning signs early can save you time and money. Keep an eye out for the following clues:
- A fan that keeps running while the registers blow cool air
- Grinding or high-pitched squeals from the blower
- A flame that burns soft and yellow rather than steady blue
- Repeated shutdowns just seconds after the burners light
- Clicking and a glowing igniter with no burner flame
- Booming or banging at light-off from delayed ignition
- Soot, rust, or moisture near the furnace cabinet or vent pipe
- Frequent on-off cycling that never reaches the thermostat setting
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 (469) 423-7181 for a prompt inspection.
