Why Is My Heat Pump Blowing Hot Air In Cool Mode?

image of a homeowner feeling hot and sticky due to heat pump blowing hot air in cooling mode

There’s no doubt that heat pumps are versatile. They provide year-round comfort since they can heat or cool your home, depending on your preferred settings. If it feels too chilly in the winter, then you can use a heat pump to warm up the house. If it feels too hot in the summer, then you can use the same unit to cool things down. It is easy to switch modes and change the temperature settings. However, sometimes owners find their heat pump blowing hot air in cool mode. Let’s find out why.

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Why Is My Heat Pump Blowing Hot Air in Cool Mode?

Although heat pumps are highly durable, they aren’t invincible. A heat pump that is blowing warm air in the cooling cycle is a common problem when heat pumps malfunction. Consequently, it is a good idea for homeowners to get familiar with the usual suspects. By learning more about the reasons behind this type of heat pump issue, they should be able to reduce the likelihood of a repetition occurrence. They can also perform basic heat pump troubleshooting before turning to the experts for help in implementing advanced solutions. Below are seven of the things that you should check when you experience this problem:

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1. A Broken Heat Pump Reversing Valve

heat pump operationThe heat pump’s reversing valve is the key to the heat pump’s versatility. Depending on its setting, the unit will either collect heat indoors and carry this outdoors or gather heat outdoors and push it indoors. This valve directs the flow of the refrigerant to achieve its goals. If there is a broken reversing valve, then the heat pump will not be able to perform as intended. The solution usually involves the replacement of the valve, followed by the addition of refrigerant to the system. It is a complex undertaking that requires the expertise of trained HVAC technicians.

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2. Heat Pump Thermostat Problem

heat pump thermostat not working

In many cases, the heat pump unit is behaving this way because the thermostat was not programmed correctly. Sometimes heat pumps are set to run with the fan only, in which case it will blow warm air around the house. You need to check the settings to confirm that the unit is in cool mode. If it is not, then tweak the settings. Someone could have changed it accidentally. It is also possible that the thermostat is low on battery so insert fresh ones to see if this helps. You may also check the breakers as these may have tripped.

If the problem persists, then you may be dealing with a defective thermostat. There is nothing left to do but to replace it with a new one. Old manual thermostats may be due for a replacement anyway so treat this as a good opportunity to do so. You can purchase a basic programmable thermostat model without spending much money. However, you can get great features if you are willing to shell out a little bit more.

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3. Heat Pump Refrigerant Loss

Unlike furnaces, heat pumps do not generate their own heat. Rather, they use a refrigerant to absorb heat from one place and release it in another. If there is not enough refrigerant flowing across the system, then it will not be able to do its job properly. The thermostat settings could be correct and the reversing valve may be working well but the unit will still blow hot air in cool mode. The lack of refrigerant is probably due to a leak. A licensed technician will have to repair the leak and top up the refrigerant as soon as possible.

4. Clogged Air Filter On Heat Pump

image of an hvac air filter replacement

It is the job of the air filter to catch dirt and dust. These settle on the air filter surface while air passes unimpeded. However, the layer of dirt can get so thick that it blocks the passage of air. Restricted airflow will make it hard for the heat pump to operate. This can easily be remedied by cleaning the air filter to remove the clog. It would be even better to replace this with a new filter for a fresh start. Check the manual for the manufacturer’s suggested frequency of filter cleaning and replacement. Note that the environmental conditions around your home may require you to change it more often.

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5. Heat Pump Duct Leak

Air ducts can suffer from degradation due to aging just like everything else. If your ducts are quite old, then they may have started to leak out air. This will prevent it from distributing the conditioned air across the home. Some rooms may feel cold while others feel warm. It can be difficult to find the exact location of the leaks. Call HVAC professionals to assist you in dealing with this situation. Fixing the problem will not only improve air distribution. It will also reduce energy consumption and lower monthly bills. Have the ductwork repaired right away for long-term savings and comfort.

6. Dirty Heat Pump Coil

image of a dirty heat pump coil

Due to its location, the outdoor unit of the heat pump is prone to dirt and debris. You must think about the level of dust in the environment. You must also consider pet hair, grass clippings, dried leaves, and so on. These are certain to make the heat pump coil dirty after a while. The layer of dirt will limit its ability to absorb or expel heat through the coils. That’s why it is necessary to clean these regularly. Just use a water hose at low to medium pressure to remove loose dirt. High water pressure may end up damaging the unit to be careful about the settings. If you find stubborn spots, then use a light brush to scrub them off.

You should clean the indoor coils as well. These could be harder to access so you might want to pass the job over to an HVAC technician. A heat pump tune-up service is quite affordable and you will end up with excellent results.

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7. Frosted Indoor Coil On Heat Pump

Lastly, consider the possibility that the heat pump malfunction is due to a frosted indoor coil. It may seem counterintuitive for a frosted coil to cause warm air in cool mode. However, it all makes sense if you understand how the heat pump works. Freezing can happen when moisture from the air condenses around the indoor coils because low temperatures. The ice will prevent the coil from collecting heat, causing the unit to stop working as intended. Fixing this will require some downtime for the heat pump before putting the system in fan mode. This will force warm air through the coils and hasten the defrosting process.


Do I Repair or Replace the Heat Pump?

Homeowners may wonder whether they should continue to pay for heat pump system repairs or simply replace the entire heat pump. Consider the following factors before you make the final decision:

  • Heat Pump Warranty: Check whether your system is still under warranty. If it is, then you can depend on this for free parts replacement and labor fees. It would make sense to keep the unit around at least until the warranty runs out.
  • Heat Pump Age: Heat pumps can run for 10 years or more. However, it is likely to suffer from wear and tear once it crosses the decade mark. HVAC repairs will be more frequent and a lot of people don’t want to deal with these headaches. If you want a reliable system, then get a new one.
  • Heat Pump Vs. Heat Pump Replacement Cost: It would be prudent to make calculations comparing the cost of repairs versus the cost of a replacement. Add up your repair bills in the last few years and estimate your future expenses. Getting a new heat pump may turn out cheaper than keeping your old one.
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Heat pumps will make your household comfortable no matter the season. You can make it blow cold air when it’s hot and vice versa. If it is blowing hot air in cool mode, then you need to investigate the matter. The root cause is probably one of the reasons described above. Call a professional HVAC technician for immediate assistance.

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McAllister Energy

McAllister Energy offers high-quality HVAC services in Camden County, New Jersey. We hire only the best, professionally certified technicians who conduct superior heating and cooling services. Some of our HVAC services include HVAC maintenance, heating and cooling installations, repairs, ductless systems, energy audits, and much more. All our techs provide accurate HVAC services on time, every time.

Our company guarantees affordable heating and cooling service rates. Our maintenance services can increase your home’s comfort, energy efficiency, and cost-effectiveness. We can also provide you with a highly energy-efficient HVAC replacement system that fits your budget. Your satisfaction is important to us, so all our work comes with a guarantee. Book a service appointment with McAllister Energy today. We provide free, in-home estimates.

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