Thermostat Says Heat On But There Is No Heat – Best Working Solutions 2022

Being able to see that your Honeywell thermostat says ‘heat on’ when there is no heat is one of the most irritating things as it cause not working thermostat. What could be the problem?

Such problems are typically caused by a dirty filter, thermostat malfunction, pilot ignitor, incorrect settings, or low battery. All you have to do in such a case is clean the device, double-check the thermostat settings, or replace the batteries.

What should you do if your Honeywell thermostat says ‘heat on’ when there is no heat? How can you prevent such issues like ‘thermostat heat not working’ in the future? Here’s everything you need to know. 


Common Reasons Why Honeywell Thermostat Says “Heat On” But There Is No Heat

There are several possible reasons for not working thermostat if the Honeywell thermostat says heat on but no heat.


The Thermostat Filter Is Dirty

honeywell thermostat says heat on but no heat

One of the most common reasons for such a situation is a clogged filter. All you need to do is check the filter. When the thing looks dirty, it means the airflow is restricted, and your furnace cannot run.

Try replacing the filter and see if that helps.

Ideally, you should replace your filter every two months or so. If your filter is dirty, it won’t be able to heat your place, resulting in higher bills effectively. So you won’t end up overspending.


There Is No Gas Supply

thermostat says heat on but no heat

Are you using a gas furnace? Open the valve that supplies the gas to the furnace.

Attention! In the event that this simple manipulation didn’t fix the problem and you smelled gas, you should shut off the gas supply and call a professional (gas leaks are serious).


The Heater Is Disconnected From The Power Source.

disconnect power supply

Ensure that the power has not been cut off at your electrical panel. The next step might seem obvious, but be sure to check the power switch. Does it have the ON position?


The Pilot Ignitor Might Be Dirty

dirty pilot ignitor

Another common problem that might occur is if you have a gas furnace. Turn off your furnace and remove the front panel if you feel comfortable working with different devices. Is the ignitor dirty and clogged? In that case, you would need to hire a professional team to fix it.


The Thermostat Is Set Incorrectly

thermostat set incorrectly

It could be a problem with the Honeywell thermostat itself when it says heat on, but there is no heat. Fortunately, you can check that.

The thermostat must be set to a temperature greater than the current room temperature to activate the furnace. For some, it’s preferable to set the thermostat to the highest heat setting. Don’t forget to turn the thing down before it gets too hot in this case.

After that, make sure that the system switch is set to AUTO or HEAT. Also, make sure the fan is set to AUTO or ON.


There Might Be Some Issue With The Battery

change thermostat batteries

That could be the problem if you have a battery-powered thermostat. Replace the battery if it is weak or dying. Be sure to wait a bit after you have changed the batteries so that the thermostat can adjust.

As you can see, a lot of the reasons mentioned above can be easily resolved even by someone who is not very knowledgeable about technology. On the other hand, if you do not feel comfortable dealing with such issues and if you are not sure of what to do, do contact a specialist who can help.


How To Avoid Such Issues Like “Honeywell Thermostat Says Heat On But There Is No Heat” In The Future?

With regular maintenance, you will be able to avoid various heat problems with your Honeywell thermostat which cause thermostat not working issue.

Your heating system will work more efficiently, and your central air system will last longer if you establish a maintenance schedule.


Know When To Replace The Batteries

How often should you replace your batteries?

  • Make sure to pay attention to the ‘low battery warning light on your Honeywell thermostat. Alternatively, the device may emit a light beeping sound when it is time to replace the battery.
  • In order to avoid malfunctions when you desperately need heat or cold, replace the batteries at the beginning of every new season.
  • Before going on vacation or a business trip, change the batteries in your Honeywell thermostat to prevent any problems while you’re gone.


Find out how to clean the Honeywell thermostat.

clean thermostat

The number one reason your Honeywell thermostat might be malfunctioning is that it’s dirty. This is why it’s important to learn how to clean it. Moreover, heat issues can cause not working of thermostat as well.

During a heatwave or a cold winter, the Honeywell thermostat may become one of the most touched surfaces. Cleaning the thing is also important to keep the surface free of germs.

  • Take off the cover. Some models have screws, while others have snap-on covers.
  • Dust the inside of the thermostat with a dry, soft paintbrush. There may be some debris in places where different electrical components meet. A brush won’t help much here. Take a dollar bill and slide it between the components like dental floss. You will then be able to loosen and later remove any dirt.
  • You are now ready to examine the wires. It is dangerous to try and replace any corroded or loose wires on your own. Call an electrician if you find any corroded or loose wires.
  • Replace the batteries if necessary.
  • Clean the cover and replace it on the Honeywell thermostat. Smart thermostats do not require interior cleaning.


How To Check The Honeywell Thermostat’s Accuracy

You should also check the thermostat’s calibration. If the numbers are inaccurate, the chances are high that there is something wrong with the actual device, which might be one of the reasons why it is saying your heat is on when it’s freezing cold inside your house.

To calibrate the thermostat, what will you need?

Tape, paper towel, and a glass tube thermometer. A level and a paintbrush may also be needed.

  • Tape your glass tube thermometer right to the wall an inch or two away from the thermostat. Make sure to pad the thermometer with a paper towel or a napkin to ensure that it shows the right temperature.

Devices should not be affected by outside temperatures. There are times when the hole in the wall behind the thermostat through which the wires enter the device is too large. In such a case, cold air will reach the thermostat and affect the accuracy of its readings.

  • Please wait for 10-15 minutes. The mercury in the glass tube thermometer must stabilize.
  • You should compare the readings.
  • Something is wrong with the thermostat when the temperature varies by more than one degree. It would be best if you began by cleaning the device (see the instructions above). 

To ensure that your thermostat is straight, you would need a level if it has a mercury vial inside. If it isn’t straight, loosen the mounting screws and adjust the device. 

  • Check the thermostat’s accuracy again. It looks like you will need to replace the device if the problem persists.

You should also make sure that the air is flowing as part of your maintenance routine. Regularly clean your air filters and ducts.


When Should You Hire A Professional?

You can do quite a few things on your own to fix a Honeywell thermostat that says ‘heat on,’ but there is no heat. Typically, this malfunction is caused by a small issue that you can fix quickly.


What you can doWhat you should leave to the professionals
Check the settingsIssues with the sensor
Calibrate the deviceCracked heat exchanger
Change the filterImproper ductwork
Clean the ducts and air filtersLow refrigerant levels
Clean the thermostatGas issues
Replace the batteriesDead blower capacitor


However, a minor issue may be an indication of a more serious problem. That’s why it’s important to know when to call a professional since DIY solutions can have terrible outcomes.


Thermostat Says ‘HEAT ON’ But There Is No Heat: Conclusion

You now know why your Honeywell thermostat says ‘heat on,’ but even when there is no heat.

Follow these steps:

  • Look at the settings
  • Clean your device
  • Replace the battery and the filter
  • Regularly maintain the thermostat

By following the instructions in this article, you will be able to solve all the minor Honeywell thermostat not working problems like the thermostat says heat on, but there is no heat.

Don’t underestimate the importance of regular maintenance, and know when to call a specialist, since sometimes, even the smallest malfunctions could signal a bigger problem that must be addressed by a professional. 



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