Is your furnace blowing cold air when it should be warm? Or maybe it’s not blowing out any air at all? Don’t worry, you’re not alone. This is a problem that regularly comes up for homeowners, and it can be tricky to figure out the exact cause of the problem. To help get hot air flowing back into your home, take a look at these common reasons your furnace isn’t blowing hot air, and call a professional if the problem persists.
Reasons Your Furnace Isn’t Blowing Hot Air:
1. The pilot light is out
If your furnace isn’t blowing hot air, the first thing you should do is check to see if the pilot light is out. The pilot light is a small flame that ignites the gas in your furnace, and if it’s out, your furnace won’t be able to generate heat. You can usually find the pilot light on the front of your furnace, and it will be a small blue flame. If the flame is out, you can relight it following the instructions in your furnace’s manual.
2. The furnace doesn’t have enough power
The most basic way to tell if your furnace doesn’t have enough power is to see if it’s turning on. Turn on your furnace and listen for the sound of the fan. If you don’t hear the fan running, that means the furnace isn’t getting power. You can also check to see if the furnace is getting any heat by feeling the exhaust pipe. If it’s cold, that means the furnace isn’t working.
If you’ve tried these tests and still think your furnace doesn’t have enough power, there are a few other things you can do:
- Check to make sure all of the switches are in the “on” position
- Make sure there’s no ice or snow blocking vents or pipes
- Check your breaker box and make sure nothing has tripped
3. The thermostat is set too low
The next step is to make sure that the thermostat is set high enough for your liking. Many smart thermostats track your habits and build a schedule around them – as weather starts to get colder, you may need to retrain your thermostat into setting new temperatures. If the thermostat is set too low, it will prevent the furnace from blowing hot air.
4. The furnace filter is dirty
One of the most common reasons a home furnace isn’t blowing hot air is because the filter is dirty. The furnace filter is responsible for trapping dust and dirt before it can enter the furnace, and if it’s clogged up, the furnace won’t be able to generate heat. To check if your filter is dirty, remove it from the furnace and hold it up to the light. If you can’t see light shining through, that means the filter is too dirty and needs to be replaced.
5. The blower motor isn’t working
Another thing you can check is to see if the blower motor is working. The blower motor is responsible for pushing the heated air out of the furnace and into your home, so if it’s not working, you won’t feel any air coming out of your vents. At this point, it would be a good idea to call a professional to take a look at your furnace.
6. The gas valve isn’t open
Another common reason a home furnace isn’t blowing hot air is because the gas valve isn’t open. The gas valve is responsible for letting gas flow into the furnace, and if it’s not open, the furnace won’t be able to generate heat.
To check if your gas valve is open, you can remove the cover from your furnace and take a look at the valve itself. If the lever on top of the valve is in the “on” position, that means the gas valve is open. If it’s in any other position, that means it’s closed and you’ll need to turn it on.
7. The igniter is broken
If none of the previous solutions work and you think your furnace igniter might be broken, you can test it by trying to ignite it manually. To do this, remove the cover from your furnace and locate the igniter. It will be a small metal rod with two wires coming out of it. Touch one wire to each side of the igniter and have someone turn on your furnace. If the igniter doesn’t glow red, that means it’s broken and needs to be replaced.
8. There’s a problem with the flue pipes
The flue pipes are responsible for carrying exhaust from the furnace to the outside of your home, and if they’re blocked or damaged, it can prevent the furnace from blowing hot air. To check if there’s a problem with your flue pipes, you can remove the cover from your furnace and take a look at them. If they’re blocked or bent, that means there’s a problem and you’ll need to get them fixed.
9. There’s a problem with the heat exchanger
The heat exchanger is responsible for transferring heat from the furnace to the air that’s being blown into your home, and if it’s not working correctly, it can prevent the furnace from blowing hot air. To check if there’s a problem with your heat exchanger, you can remove the cover from your furnace and take a look at it. If it’s cracked or covered in soot, that means there’s a problem and you’ll need to get it fixed.
10. You have a cracked heat pump
If you think you might have a cracked heat pump, there are a few things you can check to see if that’s the case. One of the easiest ways to tell is to listen to the sound the pump makes – if it’s making a loud noise, that could be a sign that it’s cracked. You can also check to see if the pump is leaking fluid – if it is, that’s another sign that it might be cracked. If you’re not sure whether or not your heat pump is cracked, it’s best to call a professional to take a look at it.
What do I do now?
If your furnace is blowing cold air, don’t panic! Check to see if the pilot light is out, if the furnace doesn’t have enough power, or if the thermostat is set too low- these are all common reasons why your furnace might not be blowing hot air.
If the problem persists, call AAA to take a look at your furnace and diagnose the issue today.