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Is your heat pump not working? There are several issues that could prevent your heat pump from working properly. These include the thermostat, power supply, refrigerant levels, a blocked outdoor unit, and others that we are going to be looking at very soon in the article.

Besides providing possible issues that are preventing your heat pump from coming on, we have also put together possible solutions to each these problems:
7 Reasons For Your Heat Pump Not Working
1. Thermostat Issues
If your heat pump won’t come on, the first thing you need to do is check your thermostat. Your thermostat could prevent your system from working properly. These are some of the things you need to check with your thermostat.
Thermostat settings: If your thermostat won’t come on, you need to check if your settings are all correct. If you are using a programmable thermostat, ensure that it was correctly programmed, and the temperature is set to a point you want.
Sometimes your thermostat can be accidentally adjusted by yourself or someone else.
- Solution: Double check settings on your thermostat even when you are sure that you have the correct settings. If you discover anything wrong, try setting it correctly.
Thermostat battery: Another issue that can affect how your thermostat works is a low battery. A low battery can stop your heat pump from responding to temperature adjustments from your thermostat. It can also cause problems with turning on and off your heat pump.
Some thermostats will typically flash a low battery warning message weeks before a battery completely dies. But sometimes you might miss this message especially if you were away from home.
- Solution: This is an easy fix. If your batteries are flat, gently remove the thermostat from the wall and replace the old batteries with new ones.
Thermostat wiring: A wrongly wired thermostats will always give you trouble. Each major function of your thermostat has its own connection wire. A thermostat that is not wired correctly can cause heat pump problems.
If you installed your thermostat by yourself, it’s possible that you might have missed out something.
- Solution: Check your thermostat’s wiring to make sure that every wire has the right connected terminal. And ensure there are no loose connections. You can check your thermostat’s user manual on the wiring guide.
Also read: Why is My Heat Pump Blowing Cold Air [Solutions]
2. Loss of Power to Your System
Assuming there is nothing wrong with your thermostat settings, check if power is getting through to your system. Usually, a heat pump will have two switches, one for the indoor unit and the other, for the outdoor unit.
- Solution: Look at both switches and find out if they are all on. Turn on those that are off. If everything is cool with the power switches, head over to the circuit breakers. Your indoor and outdoor unit will all have a separate circuit breaker.
- Because heat pumps are high wattage appliances, Its possible that your outdoor circuit breaker is tripped. Flip back any tripped breakers.
3. Low Refrigerant Charge
A heat pump does its job of cooling and heating with the help of a refrigerant. In the heating season, the refrigerant absorbs heat from your outdoor air and brings it into your home using the refrigerant.

A reverse of this process takes place in the cooling season, where your heat pump now works as an air conditioner.
However, sometimes the refrigerant might leak out of your heat pump system, and you will have just little of it or nothing at all. When this happens, your heat pump will:
- Not be able to heat your space. If there is no refrigerant in your system, no heat will be absorbed from the outside to warm your home. That’s why when you turn on your heat pump, you won’t have any heat coming into your home.
- Not cool your home in the cooling season because, there will be no refrigerant to absorb heat from your indoor air to dispose outside. That is why you can have no cooling coming through when you turn on heat on your thermostat.
When your system remains without the refrigerant, this causes other problems with your heat pump system. It can cause damage to the compressor which can be costly to repair.
- Solution: But if you think your system is running low on the refrigerant, its best to call in an HVAC technician to come and verify that the refrigerant charge in your heat pump.
Read also: Heat Pump Not Blowing Hot Air [8 Easy Solutions]
4. Blown Out Blower Fan Could Cause Heat Pump Problems
A blower fan helps in the process of transferring heat between the indoor and outdoor environment. It draws air into the coils to help with the heat transfer. when you have a blown-out blower fan, you may not be experiencing heat or cooling when your heat pump is turned on.
5. Non-Functional Defrost Timer:
A defrost timer helps in defrosting your outdoor unit at predetermined intervals. This is to prevent ice or frost to build up on your system. However, if you have a dead defrost timer. Your unit will not be able to defrost as much, and you will experience your outdoor unit freezing more often.
- Solution: If a defrost timer is malfunctioning, it’s smart to call an HVAC professional to come an inspect it,
6. Blocked Registers
Sometimes the HVAC system could be working properly, but the problem could be closed registers. Closed registers could make you feel like your heat pump is not working.
- Solution: Open up closed vents and registers in every room. Remove anything that is blocking them such as the rugs and furniture
7. Heat Pump Not Working- Blocked Unit
For a heat pump to run efficiently, the outdoor unit should be able to dispose the heat or absorb heat easily and freely without objects covering it. If leaves, dirt, and other debris, if find their way to your unit, your heat pump will not work properly.
Final Thought
Although there are several things that can prevent your heater from working properly. The above issues are the commonest.
We hope they have been helpful and each time you have heat pump problems, try going through out guide before calling professionals.
Resources
https://www.youtube.com/watch?v=YV9IfeUAr2o&t=58s
https://www.icsny.com/blog/should-i-cover-my-ac-unit-in-the-winter

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