Furnace Won't Light? The Ignitor Is Usually the Culprit

Hot surface ignitors are a common failure point, and replacement is usually straightforward.

Central Valley winters are short but can dip into the 30s overnight, and homes here are typically built and insulated for cooling first. That combination means heating systems often run in bursts rather than steadily, which changes how they fail and how they should be maintained.

What to check first

• Test your heating system before the first cold snap, not during it — this gives time to schedule non-emergency repairs.
• Check that vents and returns throughout the house are unobstructed by furniture or rugs.
• Watch for a persistent burning smell beyond the first 15-20 minutes of the season's first run — that's not normal.
• Confirm your carbon monoxide detectors are working if you have a gas furnace.

Why this matters in the Central Valley

Ceres, Modesto, Turlock, and the surrounding Stanislaus, Merced, and San Joaquin County communities see a wider temperature swing between summer highs and winter lows than coastal California, and that swing is hard on HVAC equipment. Systems sized or installed for a milder climate tend to underperform or fail early here. When our technicians evaluate a system related to "furnace won't light? the ignitor is usually the culprit," we're always weighing it against what actually happens to equipment in this specific climate — not general national averages.

When to call a professional

If your troubleshooting turns up anything beyond the basics above — unusual electrical smells, water pooling near equipment, ice buildup, gas odor, or a system that won't respond to thermostat changes at all — stop and call rather than continuing to test on your own. Our diagnostic visits start with the same documented process every time: refrigerant charge, electrical readings, airflow, and (where applicable) combustion analysis, with a written report before any repair work begins.