Don’t waste your benjamins! Follow our electric furnace troubleshooting guide, we will try our best to help you diagnose and repair your electric furnace without an expensive service call. Most service calls are at least $100, and with this guide you can walk through some basic troubleshooting steps and possibly fix your issue yourself!
*TAKE NOTE, WORKING AROUND YOUR FURNACE IS NOT FOR EVERYONE. PROCEED AT YOUR OWN RISK AND DO NOT HESITATE TO HAND THE JOB TO A PROFESSIONAL IF YOU ARE NOT COMFORTABLE.
First things first – the thermostat
In order to start troubleshooting your furnace, we will first need to make sure that the thermostat is working properly. First check that the thermostat is set to heat (for heat pumps set to emergency mode) and that the set-point is minimum 5 degrees above your room temperature. For a mechanical thermostat, turn the fan switch to on and also verify that the thermostat is level. Did the blower motor kick on?
What to check if the fan is not running
After you perform the thermostat checks and the fan still won’t run, next you will want to take a look at your heat pump/ furnace circuit breakers or fuses. If you do find a blown fuse or tripped breaker, take a look at the wiring in the furnace for any signs of melting or other damage. Check all of the connections for any kind of looseness or other damage. After you fix or verify that the wiring is in good shape then you can replace the fuses or reset the associated breaker.
If you find that the fan still will not kick on, you will then want to look at the furnace control circuit board, thermostat, fan relay, blower motor, or the control transformer as possible sources of the issue.
If the fan does turn on
Once you have the fan working, set the thermostat to the auto fan setting. Let it run for a minute and then check to see if the air coming out of the vents is starting to get warm.
If you can’t get any hot air out of the vents, you’ll want to take a look at the element, the limit control, the control board, the sequencer, or a wiring issue like a burnt or loose connector.
Heat output troubleshooting on an electric furnace
If you aren’t getting any heat output, or very little heat, the next thing to check is the temperature difference of the furnace. Find the closest vent to the furnace and start there to take your readings. Cross check that with the temperature of the closest return grill. Easiest way to verify temperatures is an infrared thermometer.Look for the manufacturer’s label plate on the inside of the furnace and compare the nominal range with your readings.
If you have measured a temperature rise that is lower than the minimum on the plate, you’ll want to start with checking that all of the elements are working as they should.
On the other hand, if your temperature rise is more than the recommended maximum range, you’ll want to check that the blower motor is operating correctly and if it is, then the speed of the blower may have to be dialed up.
Anytime you perform these adjustments, make sure to double check and watch how the furnace operates over a full heating cycle to confirm that the issue has been fixed.