Furnace Repair in Arnold, MO
Furnaces here run from October through April. If yours quits, tell us what it's doing and a licensed contractor who covers Jefferson County will get in touch.
Tell us about the job
It takes about a minute.
Seven months of work, most nights near freezing
Furnaces in Arnold run from October through April. On the nights in between, when the low sits around 25°F, the burner cycles on and off for hours trying to hold the house steady. Every one of those cycles asks the igniter to light the burner again, and that part wears a little more each time. Eventually it fails to light at all, and the furnace either won't start or starts and then shuts back down.
57.5% of homes here heat with electricity, so when the power goes out, the furnace stops no matter what shape it's in. Jefferson County has seen 11 winter storms and 53 damaging wind events over the past ten years, and statewide, 19% of households went at least 24 hours without power in 2024. Most furnaces restart on their own once power returns, but one that was already struggling before the outage may not.
- 7 months
- October through April, your furnace is on duty
- 25°F
- the average winter night it heats against
- 11 winter storms
- in ten years, the nights a failure hurts most
NOAA nClimDiv, 1991–2020 normals
- Why won't my furnace turn on?
- Most often the thermostat isn't calling for heat the way it should, or power isn't reaching the furnace. Check that the thermostat is set below room temperature and has fresh batteries if it uses them. Next check the furnace switch, which looks like a light switch near the unit, and the breaker it runs on. If those are fine, the igniter or a safety switch inside the furnace may have failed, and that's a job for a contractor to diagnose.
- Why is my furnace blowing cold air?
- A furnace blowing cold air is usually still in its startup cycle, when the blower runs before the flame has fully heated the air. If it stays cold for more than a few minutes, check your air filter first. A clogged filter can choke the airflow enough that the furnace can't build heat properly. If the filter looks fine and the air is still cold, the igniter or gas valve may not be lighting the burners, and a contractor will need to look at it.
- Why won't my furnace pilot light stay lit?
- A pilot light that won't stay lit usually points to a weak or dirty thermocouple, the small sensor that tells the gas valve the flame is burning. If it can't sense the flame, it shuts the gas off as a safety measure even though the pilot was lit a moment ago. A draft blowing out the flame or a partly closed gas valve can also cause this. Since this involves the gas supply, have a contractor check it rather than repeatedly relighting it yourself.