How To Fix A Furnace With No Heat? Here are three easy checks.
This advice is geared for anyone who has little to no experience with how to fix a furnace.
If your furnace is not heating, there are actually three easy checks you can do before calling a professional. These may fix your furnace that is not heating. If you have a furnace no heat issue, we recommend:
1. Check the thermostat and make sure it is set to heat mode
2. Set the thermostat to “on” instead of “auto” and make sure there is power going to the furnace.
3. Do a hard reset of the furnace by removing power for about 10 seconds.
If after you check these three things, the furnace is still not working, we recommend calling a professional to do a more in depth look for the problem.
1. Check the thermostat and make sure it is set to heat mode
If you’re experiencing a problem with your furnace, the first thing to check is your thermostat. Go to the thermostat, don’t touch it, don’t make any adjustments. Just look at the thermostat.
Is it properly set on heat?
On the thermostat there is a heat/cool/off switch. The switch should be in the heat mode.
Also, the temperature setting should be set above the recorded room temperature. The term for that is that your thermostat is “calling for heat.” This is telling the thermostat that “yes I need you on.”
Sometimes you thermostat is just not calling for heat or if it is a programmable thermostat where the settings have changed and you are not aware of the change.
2. Set the thermostat to “on” to make sure there is power going to the furnace
We want to make sure there is power to the furnace.
Many times the the furnace is completely dead, not doing anything. In this case, we want to make sure there is not a power problem.
There’s a really simple way for you to check for power to the furnace that is not heating.
Let’s go back to the thermostat. There is another switch for your fan. It will either be marked fan or blower. This has two settings: “auto” and “on.” (Some will have a circulate mode but typically just the two.)
Set your thermostat to the “on” position.
By putting the thermostat to the “on” position you are telling the blower to come on and to run non-stop. When you switch it to on you should hear the furnace blower come on. Go to a nearby register. You should feel air blowing out of the register. If you do not, we know that we have some sort of power issue.
We have given the furnace a direct call for the blower to come on, and if it’s not coming on, there is a power problem.
3. Do a hard reset of the furnace by removing power for about 10 seconds
Let’s try a hard reset of the furnace.
Many furnaces today have multiple circuit boards with many safety control features. These control features can sense when your furnace is having a problem turn itself off for safety reasons.
Sometimes the furnace could turn itself off due to a power outage or something that isn’t actually a problem so you can try resetting the furnace to see if it comes back on.
In order to do a “hard reset” you simply remove power to the furnace. There should be a power switch, an external power switch on the side of the furnace that looks much like a light switch on the wall. Turn off the switch for about 10 seconds and then turn it back on.
If you do not have a switch to power on your furnace, your furnace may use a simple wall plug. Unplug the furnace, wait ten seconds then plug it back in.
You have now done a hard reset of the furnace. It should have cleared out any faults and so it should have a good call for heat. At this point you should hear action in the furnace.
Bonus tip for a furnace that is not heating: Change Your Filter
Make sure the filter has been changed and is not blocking air flow. A dirty filter can cause the airflow to be blocked to such an extent that your furnace will turn itself off for safety reasons. Change your filter, do a hard reset of your furnace and see if that helps the furnace start working again.
If You Still Have A Furnace Not Working…
If after these checks you still are not getting heat from your furnace, it’s best to schedule an appointment with a professional. There is something larger going on. You have now checked the most rudimentary things: the thermostat is on, it is calling for heat, there is power to the furnace, there is a clean filter. Now time to have a professional take a look.
