Furnace Not Working? A Utah Homeowner's No-Heat Troubleshooting Guide
Nothing sharpens the mind like waking up to a 58-degree house in a Utah January. Before you call for furnace repair, here are the things worth checking yourself, and the symptoms that mean you should not wait.
Check these first
- Thermostat. Set to Heat, set point above room temperature, fresh batteries.
- Filter. A packed filter trips the limit switch and shuts the furnace down. Replace it.
- Power switch. Most furnaces have a light-switch-style disconnect nearby. Make sure it is on.
- Breaker. Check the panel for a tripped breaker.
- Gas valve. The handle should be parallel with the pipe.
- Blower door. If the panel is not fully closed, the safety switch prevents startup.
Symptoms that need a technician
Furnace clicks but does not light
Usually a failed hot surface ignitor or a dirty flame sensor. Both are quick fixes for heating repair technicians and both are on every truck we run.
Furnace short cycling
The furnace runs for a minute or two and shuts off, over and over. Causes include a clogged filter, a failing limit switch, a blocked flue, a bad flame sensor or an oversized furnace. Read our full post on furnace short cycling below.
Blowing cold air
The blower runs but the burners never fire. Ignition, gas supply or control board.
Burning or gas smell
A brief dusty smell on first startup of the season is normal. A persistent gas smell is not. Leave the house, call the gas company, then call us for emergency heating repair.
Carbon monoxide detector sounding
Get everyone out and call 911. A cracked heat exchanger is the most likely cause and the furnace should not be run until it is inspected.
Repair or replace?
A 20-year-old furnace with a cracked heat exchanger is not worth repairing. A 9-year-old furnace with a bad ignitor is. If you are unsure, we give honest numbers on both furnace repair and furnace replacement in every Utah city, including Logan, Park City and Sandy.