Heat Pump Not Cooling Below 80 Degrees [Solved]

Is your heat pump not cooling below 80 degrees? Is so then this article will help you troubleshoot this problem. There could be any number of reasons why your heat pump is not cooling enough. These include:

• Too hot outside environment
• Dirty air filters
• Undersized air conditioner
• Leaking refrigerant
• Blocked condenser unit
• Leaky ductwork

Also read: Heat Pump Not Blowing Cold Air [Solved]

Why Is My Heat Pump Not Cooling Below 80 Degrees?

While there could different reasons why your heat pump is not cooling enough, the following are the most common ones.

1)Too Hot Outside Environment

If your heat pump is not cooling enough, your outdoor environment could just be too hot for your air conditioner to work properly.  Heat pumps and air conditioners are designed to work effectively if the outdoor temperature does not go beyond 92 degrees.

If you live in regions that experience extreme temperatures in summer, exceeding 92 degrees, you might experience your system not cooling down to your set temperature.

In case your outdoor temperature is above the recommended operating temperature, try supplementing your heat pump’s cooling. You can do this by turning on either ceiling fans or any other domestic fans to help cool yourself down.

Otherwise, if your outdoor temperature is below 90 degrees but your heat pump is not cooling your home below 80 degrees, look out for other issues.

2) Dirty Air Filters

Dirty and clogged air filters could be the reason your heat pump air conditioner is not cooling enough. Think of an air filter like engine oil. If you don’t change your oil on time, your engine will not work as it should.

Dirty air filters will prevent your heat pump from cooling to the set temperature and can also prevent your heat pump from heating your home to the set temperature.

Air filters trap dirt and other contaminants from air before it gets into your ac system. Because filters work all time when your heat pump is running, they can quickly become dirty and clogged.

What happens if you don’t clean air conditioner filter?

When air conditioner filters become very dirty and clogged, they can:

• Restrict airflow to the evaporator coil
• Cause dirty air to bypass the filter
• Cause your heat pump ac to work inefficiently
• Results in hefty electricity bills

If your air filters are clogged, dirty air will bypass them and get into your ac system. This dirty air can deposit dirt into the evaporator coil. Dirty and other build up will insulate the evaporator coil and reduce its ability to absorb heat from your air indoor air.

Because of that, your indoor air will somehow be cooled but not enough to come down below 80 degrees.

How do I replace a dirty heat pump air filter?

If you believe your air filter is dirty, you need to check its status.

Find the location of your filter. Usually, air filters are found at the return ducts or at the heat pump’s air handler cabinet.

Pull your air filter out and look at it. A dirty air filter is usually easy to tell, and you’ll definitely need to clean it or replace if necessary and, this can solve the whole cooling problem. 

3) Undersized Heat Pump AC

If your heat pump ac is too small for your home, your system will overwork to try and keep your living spaces cool. But it will be hard for your system to cool your home below 80 degrees.

The cooling power of a heat pump ac is measured in BTUs. Bigger rooms or homes will need an air conditioner with a much higher Btu rating.

However, if you have an undersized heat pump ac, there are few things you can try to do to improve cooling. These include:

• Closing doors and windows to the outside
• Sealing gaps between doors and between windows
• Turning off heat producing appliances that are not in use

Open doors and windows will allow outdoor air to come and displace the cooler indoor air, this will make it harder for the undersized ac to even provide a bit of cooling. But closing them together with sealing the gaps between them, can significantly improve your undersized air conditioner’s cooling.

You can also try turning off appliance that produce heat when you are not using them. Appliances such as plasma TVs that produce heat, can be turned of when not in use.

4) Leaking Refrigerant

A heat pump ac with a leaking refrigerant can not cool your home enough. And in the worst-case scenario, when you have a leaking refrigerant, your system won’t be able to cool your home at all.

A refrigerant is a chemical used in air conditioning systems and refrigeration to transfer heat between two environments. The commonly used refrigerant in air conditioning systems is the R22 also known as freon.

The refrigerant runs in a closed system. That means that it’s designed to run without running out.

However, there are certain conditions and circumstances that could cause your air conditioning system to develop leaks. And this could cause the refrigerant to escape.

Can I add Freon to my AC unit myself?

Yes, its possible but not recommended. If you believe your system is running out of the refrigerant, I wouldn’t advise you to try and fix this problem yourself unless you really know what you are doing. In other states, there laws in place regarding the recharging of the refrigerant.

My take is, if your system is running out of the refrigerant, call a licensed HVAC technician. A professional will be able to pinpoint the leaks and seal them off before recharging your system with a refrigerant.

5) Blocked Condenser Unit

A blocked condenser unit could be another reason your heat pump is not cooling your home enough. The condenser unit is like the gateway for heat.

The condenser unit has coils where the gaseous refrigerant passes and releases heat.

However, with time, dirt, foliage, and other objects can build up on the condenser unit and make it hard for the heat pump to dispose heat. This will prevent your heat pump system from cooling down your home properly.

There are somethings you can do to keep your condenser clean and free of debris. These include:

• Regularly cleaning up the condenser unit’s surroundings
• Removing debris from your condenser unit
• Trimming foliage to allow good airflow around the condenser unit.

Read also: AC Unit Blowing Hot Air Outside [Solved]

6) Leaky Ductwork

If your heat pump ac is not cooling below your set temperature, you might be dealing with a leaky ductwork. Ductwork ensures that the cool air is distributed throughout your living spaces.

There are different things that can cause leaks in your ductwork such as age and rodents or other small animals. When rodents make their home in the attic, they can cause considerable damage to your ductwork.

With time, air ducts can disconnect or have leaks. When this happens, the air from your heat pump system can escape before getting into your living space. Because of that, your ac won’t cool your home enough.

If you are a DIY kind of a person, you can try to find parts of the ductwork with leaks or disconnections.  Leaks can easily be sealed without calling professional.  But if they are hard to locate, then call professionals for help.

How Can I Make My Heat Pump More Efficient?

There are a few things you can do to make your heat pump work better and efficiently. These include:

• Cleaning or replacing air filters on time
• Observing scheduled annual HVAC maintenance
• Cleaning your condenser unit when you see dirty and other objects on it. Always ensure your outdoor unit is not covered.
• Cleaning the surroundings of your heat pump condenser unit

Final Thought

We hope this guide on dealing with a heat pump not cooling below 80 degrees has been helpful. And we also hope you have been able to fix this problem. If the problem is not solved after going through our guide, its perhaps best to call local HVAC experts for help. Thanks for reading.

Tim David

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