Every time your thermostat calls for heat, the furnace works through 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 Simi Valley, CA, 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.
Cooling trouble instead? See AC Repair.
Warning Signs for Furnace Repair
The sooner you notice these red flags, the easier and cheaper the fix. Watch for these telltale signs:
- The igniter glows and clicks, yet no flame ever appears
- A flame that burns soft and yellow rather than steady blue
- Loud booms at startup caused by delayed ignition
- Short cycling every few minutes without reaching the setpoint
- Grinding or high-pitched squeals from the blower
- Air moving through the vents that never gets warm
- Repeated shutdowns just seconds after the burners light
- Rust streaks, soot, or water around the cabinet or flue
Act Before It Gets Worse
Left unchecked, even a small fault or temperature swing often signals a system working its way toward a breakdown. Call (805) 209-1677 at the first sign of trouble.
