When your furnace won’t start on a cold Spokane morning, don’t panic. Before you call for help, run through these seven quick checks. Most take less than a minute, and they solve the problem more often than you’d think.
1. Check the Thermostat
Make sure the thermostat is set to HEAT and the temperature is set at least five degrees above the current room temperature. If the display is blank, replace the batteries. A thermostat in COOL mode or with dead batteries is the most common reason for a “dead” furnace.
2. Check the Furnace Power Switch
Every furnace has a power switch that looks like a regular light switch, usually mounted on the unit or on a nearby wall. Make sure it’s in the ON position. During summer maintenance or cleaning, these switches often get bumped off by accident.
3. Check the Circuit Breaker
Head to your electrical panel and look for the breaker labeled “Furnace” or “HVAC.” If it’s tripped to the middle or OFF position, flip it fully off and then back on. If it trips again immediately, stop and call a professional—there may be an electrical issue.
4. Check the Air Filter
A severely clogged filter can cause the furnace to overheat and shut down on its high-limit safety switch. Pull the filter out and hold it up to the light. If you can’t see light through it, replace it and wait 30 minutes for the unit to reset.
5. Check the Gas Valve
If you have a gas furnace, make sure the gas valve on the supply line is open (the handle should run parallel to the pipe). If you smell gas at any point, leave the house immediately and call your gas utility from outside.
6. Check the Condensate Drain
High-efficiency furnaces produce water that drains through a condensate line. If that line freezes or clogs—common during Spokane cold snaps—the furnace shuts down as a safety measure. Look for standing water around the unit.
7. Check the Flame Sensor
If the furnace starts but shuts off after a few seconds, the flame sensor may be dirty. This is a small metal rod in front of the burners. While cleaning it is a simple job, it involves opening the furnace cabinet, so many homeowners prefer to let a technician handle it.
When to Call a Professional
If you’ve run through all seven checks and the furnace still won’t start—or if you notice strange smells, loud banging, or the breaker keeps tripping—it’s time to call in the pros. Electrical issues, cracked heat exchangers, and gas problems should always be handled by a licensed technician.
Frequently Asked Questions
Why does my furnace click but not start?
A clicking sound usually means the igniter is trying to light but failing. This can be caused by a dirty flame sensor, a faulty igniter, or a gas supply issue. If the clicking continues without ignition, turn the furnace off and call for service.
How often should I replace my furnace filter in Spokane?
During heating season, check your filter monthly and replace it every 1–3 months depending on the type. Homes with pets or during wildfire smoke events may need more frequent changes.
Is it safe to reset my furnace myself?
Yes—using the power switch or breaker to reset the furnace is safe. Most furnaces also have a reset button near the burner compartment. If the furnace needs frequent resets, though, that’s a sign of an underlying problem that needs professional attention.
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