When your thermostat says heat on but no heat, it can be frustrating. There are many things that can cause this to happen and some of them aren’t as difficult to fix as you might think. In this article, we will go over a few common reasons why your thermostat might say heat on but no heat and the best solutions to these problems.
Let’s get this fixed!
The Thermostat is not Programmed Correctly
If the thermostat is not programmed correctly, it may not be communicating with the furnace or heating system.
This means that your thermostat might not be able to turn the heat on or off, or it might not be able to adjust the temperature. If your thermostat is connected to a furnace, you can verify if the problem is with the thermostat by turning the furnace on manually.
If the furnace works when you manually turn it on and the thermostat does not, then it may be that the thermostat is not programmed correctly and may need to be reprogrammed. Check your owner’s manual to see if this is something that you can do yourself. Otherwise, you will likely want to contact an HVAC professional.
The thermostat is broken or not working
If you have verified that the thermostat is connected correctly and programmed correctly and it still isn’t turning the furnace on or off or adjusting the temperature, then it is likely that the thermostat is broken.
There are two common issues that could cause a thermostat to break and stop working.
-The first is that the thermostat runs out of batteries. When this happens, the thermostat will stop working and the heat will not come on or go off. We have discussed how to replace the batteries in a thermostat here.
-The second common issue that causes a thermostat to break is a short circuit. Sometimes, when a thermostat short circuits, it will smoke and catch fire. If this happens, you will need to replace the thermostat. A plumber can do this for you as well.
The Thermostat Is Out of Calibration
Another possible reason why your thermostat says heat on but no heat is that the thermostat is out of calibration. This means that the thermostat is not properly reading the temperature and is incorrectly turning the heat on and off.
When a thermostat is out of calibration, it will usually display an error message that says something along the lines of “out of calibration” or “needs calibration”.
If this happens, and your thermostat says heat on but no heat, you will want to recalibrate your thermostat. Doing this will fix the issue and ensure that your furnace is working properly.
Calibrating a thermostat is usually pretty easy to do and can be done by anyone. The first thing that you will want to do is make sure that the thermostat is set to heat, not cool. Now, push the SET/OFF button three times. This should recalibrate the thermostat. Some systems work differently though so check the manual of your system.
It is also possible that the sensors in the thermostat are dirty or broken. Check the manual of your thermostat to see how you have to deal with this.
If there is no problem with the thermostat itself, we can look at the other parts of the installation. Some homes use hot air to heat and have a furnace. Other homes use hot water to heat and have radiators or floor heating.
Check what you have before you read further.
Air-based central heating: The Furnace is Broken or needs maintenance
Another common reason why your furnace might not be working or your thermostat might say heat on but no heat is that there is something wrong with the furnace itself.
There are a few different things that could cause a furnace to break or stop working properly that will cause this issue.
Check if you see an error code on the display of the furnace. Inspect around the furnace to see if you notice anything unusual (water dripping, noises etc.).
Check the manual of your furnace. Restarting can make it work again. Check with a repair technician if needed.
If the furnace is working properly, check the air vents.
Make sure that these are not covered or blocked. If the vents are clogged with debris, you will want to vacuum them out. If they are clogged with dirt and debris, you will want to use a shop vac to suck the debris out.
Air ducts should be cleaned often to check if they don’t contain too much dirt and dust.
There are other things that can cause this problem and some troubleshooting might be needed. Call a plumber if needed.
Water-based central heating: There is a problem with the heater
Another possible reason why your thermostat may say heat on but no heat is that there is a problem with the heating system.
Modern heaters often display error codes. You can Google these to see what is going on. It can be anything from a problem with the electrical wire to a faulty sensor. In some cases, you will have to call a plumber to get it fixed.
Central heaters often use gas or electricity. For this reason, you have to be careful. Don’t close or open valves without knowing what is going on!
If the heater is working fine, you should check the water pipes. Make sure that there is no water leak.
Also, check the radiators or floor heating. It is possible that air has built up in them. You might have to release this. Radiators can also contain dirt that needs to be removed from them before they work properly again.
There are other things that can cause this problem and some troubleshooting might be needed. Call a plumber if needed.
Conclusion
When your thermostat says heat on but no heat, it can be frustrating and confusing. There are many different reasons why this could happen, and some of them aren’t as difficult to fix as you might think.
If you are experiencing this issue, start by checking your thermostat to make sure that it is connected correctly and programmed correctly. If not, you can usually fix the problem yourself. If it is connected correctly but still isn’t working, it is likely broken and needs to be replaced.
If this doesn’t work, there could be a problem with the furnace or heater.
If this doesn’t work, there could be a problem with the vents, radiators or pipes in your home.
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