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Is your AC heat mode not working? If it isn’t, don’t worry because in this article we will be looking at everything you need to know about an air conditioner with heat mode that is not working.

And because we hate to leave you without solutions, we have put together solutions for each of the issues we’ll look at. Some reasons your ac heat mode is not working include, AC defrosting, thermostat issues, tripped circuit breaker, dirty air filters and of course if your AC has no heating functionality.
How Does an Air Conditioner Heat Your Home?
An Air conditioner works pretty much like a heat pump when it comes to heating your home, and when it comes to cooling your home too. But it should be noted that not all air conditioners have the heat mode functionality. For An AC with heat mode capabilities, it is equipped with a heat pump.
And uses the refrigerant to absorb heat from the outdoor air and transfer it into your indoor living spaces.
Why is My AC Heat Mode Not Working?
There are quite a few reasons your AC heat mode is not working when you try to set it so. But let’s look the commonest of the reasons below:
1. Your AC Is in Defrost Mode
Your air conditioner could not be heating your living space simply because it is in defrost mode. This usually happens if your outdoor unit is covered with ice or snow. When your ac is defrosting, it will give you cool air or at least not blow air.
Your need to give it at least 10 minutes before it can start blowing warm air inside.
If you wait for few minutes and it still can not go on heat mode, then move to the next step.
2. Thermostat issues
If you are reading this second step, your ac heat mode probably isn’t working yet. The next thing you want to do now is check for any issues with your thermostat. Make sure you check if:
- Your thermostat battery is low: A low battery in your thermostat usually causes issues such as, your air conditioner not responding to cooling and heating changes, your ac having difficulties turning on and off. Low battery could likely cause your AC not to go on heat mode when you try to set your thermostat to head mode.
- Your thermostat is compatible with your AC. If you are using another thermostat rather than one that came with your ac, its possible that you thermostat has compatibility issues with your air conditioner.
- Your thermostat is set ‘to heat’: you want your ac to heat your space so you will double check your thermostat to make sure it is set to heat instead of ‘auto’. Not only that, you need to set the temperature higher than the cooling temperature for you to feel the heat.
Solutions to thermostat issues
- If you think your thermostat battery is low, you can easily replace it with a new one, this is the easiest fix.
- For compatibility issues, check the manual of your air conditioner for thermostats that are compatible with your AC
- On top of all, make sure that your thermostat has the correct settings as we have discussed above.
3. Circuit Breaker Tripped
This may sound no brainer, but you will be surprised to know how often a tripped circuit breaker prevents your Ac unit from doing its job.
Because Air conditioners are high wattage appliances, it is not uncommon for a breaker to trip when they are working.
- If you are using a heat pump, you can check the circuit breaker for both the indoor and the outdoor unit. Of course, tripped circuit break is an easy fix that you can carry out yourself.
- Resetting a tripped breaker, should bring back your AC.
4. Your AC Has No Heating Functionality
It is not unusual for many homeowners to think that all Air conditioners have heating functionality. But if your AC is not equipped with a heat pump, its not going to heat your space. If you want to find out if your AC can be used for heating, check your user manual.
Having a ‘heat’ button on your thermostat does not necessary mean that your AC has heat mode.
5. Clogged Air Filters
Air conditioners have air filters that ensure that your unit is working as intended and efficiently. These air filters, need to be cleaned, to keep your AC unit working in good condition.
Proper and regular maintenance will always prevent unforeseen issues and costly break downs with your Air conditioner
If air filters are not cleaned or changed, dirt will accumulate on them, and they will eventually get clogged. If your air filters are clogged, they can affect things such as
- Your AC units’ cooling.
- Your Ac’s heating
- Overall working system of your AC
- Sometimes dirty air filters will cause your indoor AC unit to leak water
Luckily, its so easy to deal with filters that are dirty. You can clean them with just water and a bit of soap. But make sure you dry them completely before putting them back in their place.
FAQ
How do I set my AC to heat?
By adjusting the operating mode on your remote controller, you can set your AC to heat. Usually, the heat mode is represented by the sun symbol.
Most Ac units allow you to change operating modes like:
- Dehumidifier mode
- Fan mode
- Heat mode
- Cooling mode
What symbol is heat on air conditioner?
On the remote controller of your air conditioner, the sun symbol represents the heat mode.
Can I use AC as heater?
Not all AC have heating functionality. Only air conditioners that are equipped with heat pumps can be used for heating. You can check the manual for your AC unit if it has heating capability.
Alternatively, before getting an AC unit, you can talk to the seller and let them know that you need an AC unit that can be used for heating. Proper maintenance of your AC should prevent AC heat mode not working issues.
They should be able to advise
References
https://www.energy.gov.au/households/heating-and-cooling
https://www.rsi.edu/blog/how-to/furnace-maintenance-101/
https://www.energystar.gov/products/central_air_conditioners

HVAC tech with over 30 years of experience. Retired and doing repair work on the side around Madison County, AL.