Pre-Winter Furnace Checklist for Antelope Valley and Santa Clarita Homes

The first truly cold week of the year is the busiest week for heating repair in the Antelope Valley. Furnaces that sat idle through a 100°F summer are suddenly asked to run all night, and the same handful of parts fail in house after house. A little preparation in October and November avoids most of it.

What you can do yourself

1. Replace the filter. Desert wind and dust load filters fast. A clogged filter makes the furnace overheat and shut off on its high-limit switch — which feels like "the furnace blows cold air." A MERV 8–11 pleated filter is a good balance for most homes.
2. Test the heat early. Turn the thermostat to HEAT and raise it a few degrees on a mild afternoon. A brief dusty smell the first time is normal; a smell that lingers is not.
3. Check the thermostat. Replace batteries and make sure the fan is set to AUTO, not ON.
4. Clear around the equipment. Keep storage away from the furnace closet and keep sand, weeds and debris away from any outdoor heat pump.
5. Test smoke and carbon monoxide alarms. Every home with a gas furnace should have working CO alarms near sleeping areas.

What a professional tune-up covers

A technician's furnace tune-up goes beyond what a homeowner can safely do:

• Clean the flame sensor and measure its signal — the top cause of winter no-heat calls
• Inspect the igniter for cracks before it fails on a cold start
• Test the inducer, pressure switch and limit switches
• Check gas pressure and temperature rise
• Perform a combustion and carbon monoxide test and inspect the heat exchanger
• On heat pumps, test the defrost cycle, reversing valve and auxiliary heat

Warning signs to act on now

• The furnace won't ignite or clicks repeatedly
• The furnace is blowing cold air
• The heater is making a loud noise, especially a bang at start-up
• The furnace is 15+ years old and needed repairs last winter — it may be time to compare new furnace cost and financing

Mobile and manufactured homes

If you live in a mobile home in Lancaster, Palmdale, Rosamond, Mojave or Lake Los Angeles, also look under the home for torn belly wrap or a disconnected crossover duct. See our mobile home HVAC repair page for details.

Book before the rush

DC Air and Heating performs pre-winter heating checks across the Antelope Valley, Santa Clarita Valley and Kern high desert. Call (661) 310-3340 to schedule.