A furnace that won't start on a cold night is stressful. Here are the usual culprits — and the line where DIY stops and safety begins.
Start with the thermostat
Set it to HEAT, a few degrees above room temperature, and replace the batteries if it's blank.
Check power and the switch
Furnaces have a wall switch that looks like a light switch — make sure it's on — and check the breaker.
Check the filter
A badly clogged filter can trigger a safety limit and shut the furnace down. Replace it if dirty.
Pilot light or ignitor
Older units have a pilot light; newer ones use an electronic ignitor. If the system tries to start and fails repeatedly, the ignitor or flame sensor may need service.
When to stop and call
Safety first: If you smell gas, leave and call your gas utility, then us. Gas, ignition, and heat-exchanger issues should always be handled by a licensed technician.
Need a hand? NC Climate Control serves Archdale, Trinity, High Point, Greensboro & Winston-Salem. Call (336) 555-0100 for fast, honest help.
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