Come winter, we all need our furnaces. They’re how we heat our homes and keep comfy. Unfortunately, furnaces can break down. A common issue a lot of furnace technicians troubleshoot has to do with the blower.
What do you do when the furnace blower won’t kick on? There are many different reasons why a furnace blower won’t kick on:
1. Your Furnace Blower’s Purpose
Before we explore the different possible reasons why your furnace blower won’t kick on, let’s discuss the purpose of a furnace blower.
Your furnace blower blows hot air created in your furnace and circulates it to various spaces throughout your home. The blower does this through a spinning fan. The hot air then travels through ducts and vents to various destinations.
Your furnace either has one of two blower motor types. There’s single-speed motors which operate at full capacity according to your thermostat and variable-speed motors which go on and off in a high-efficiency operation.
2. Check the Furnace Circuit Breaker
Your furnace – like any other source of power – can trip a circuit. Before you schedule a technician’s visit, there are furnace blower troubleshooting steps you can take at home. This is one.
If you see your furnace circuit breaker has tripped, reset it and give the furnace time to calibrate itself back to a normal heating cycle. If you are not confident about the process, contact a furnace repair service for help.
3. Check the Furnace Thermostat
Yes, it seems like an excessively simple step but if your thermostat isn’t set to an appropriate temperature, you’ll find your furnace blower isn’t kicking on. Set it too low and your furnace has got nothing to go on to activate it when the house grows cold.
Alternatively, you may notice a low battery or identify some wiring issues. Regardless of the trouble, a thermostat fix is usually inexpensive.
4. Check the Furnace Filter
A clogged filter can kill airflow rather quickly. If you aren’t regularly cleaning or replacing your furnace filter during use, it’s likely it’s clogged. When this happens, you may also hear your ductwork shaking or your furnace overheating without sending heat throughout your home like it should. Ideally, replace your furnace filter once every month or two.
5. Try ‘Fan Only’ Mode
If you have tried everything on this list so far and your furnace still isn’t working like it should, turn your furnace off. Wait a few minutes. Turn your thermostat to ‘fan only’ mode.
If you hear your blower turn on, you know this isn’t where the problem lies. If your blower fan does not start, it is likely either a wiring issue or motor problem and that only an HVAC technician can diagnose, remedy, and solve.
6. Furnace Motor Reset Button (step 1)
If your motor is overheating or there an electrical issue, you may notice the switch will trip and everything will shut down. Most electric motors have a reset switch.
To find it, first cut the power at the circuit breaker. There should be a switch near the furnace in red. It looks like a light switch. Turning it off, cuts power to your furnace.
7. Inspect Your Furnace Blower (step 2)
Use a screwdriver to remove the blower compartment covering. Inspect the blower wheel and motor. If it feels hot, give it time to cool. Once it’s a normal temperature, there should be a small red or yellow button on the side of the blower motor.
Alternatively, it may be on the back of the motor housing. Flick this. This is how you reset your furnace motor. It may fix your sisue.
8. Your Furnace Air is Cold and Not Warm
Sometimes a furnace blower motor will actually be working but will only push out cold air. Assuming you’re getting a steady flow of cold air, the issue is likely not with the furnace blower.
Instead, it’s probably your heat exchanger or burner which isn’t working. If your furnace flame is yellow, red, or orange, it’s a sign there’s debris buildup on the burner. Note the flame should be blue.
9. Your Furnace Blower is Making Noises
Some furnace blowers will turn on intermittently or try to turn on and fail. Both of these processes can cause noises. Squealing or screeching is common, generally a sign of a damaged belt or bearing trouble. The motor can rattle, clank, or bang, which typically means there’s a broken part somewhere in there that needs to be removed and repaired. Loud banging indicates a disconnection or permanent damage.
Ultimately, with any noise, turn off your furnace and call a furnace technician immediately. Noise isn’t a good thing. It’s not something to be ignored. It’s indicative that there could be something more serious about to happen.
10. Does My Furnace Blower Need A Replacement
If your furnace blower won’t kick on at all, it is likely a sign that it is inoperable. A new motor is probably needed. That said, a technician’s assessment is required.
A lack of airflow can be from a bad relay, a fan control issue, or a faulty thermostat. There are various points in the overall furnace system wherein breakdowns can occur.
