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Do Heat Pumps Work In Cold Winter (Real Case And Expert Advise)

When your heat pump fails to cool, it can seriously impact the enjoyment of summer. After all, the last thing you want is to walk into a stuffy house after a day of enjoying the sunshine. Sometimes, fixing the issue with your heat pump’s cooling capability is as simple as changing the filters, but other problems may require the expertise of professionals. Therefore, when your heat pump isn’t cooling, use this guide for troubleshooting, so you can properly enjoy the heat of summer.


What is a heat pump?

In simple terms, a heat pump cools or heats your home by capturing heat from one area and transferring it to another. In warm months, the heat pump captures the heat from inside your home and transfers it outside to cool the house.


In colder months, the heat pump captures heat from outside and brings it indoors to heat the house. Even when the outdoor temperature is low, there is still enough heat energy outside for the pump to capture and transfer indoors.


Why is my heat pump not blowing cold air?

Thermostat issues
If your thermostat is set to heating mode, it will only distribute warm air. A simple way to resolve this is

a) check the temperature setting on the thermostat

b) switch to cooling mode.


Stuck in heating mode
If your thermostat is set to cooling mode, but you notice the heat pump isn’t blowing cold air, a stuck reversing valve could be the issue. A heat pump stuck in heating mode won’t switch to cooling mode, preventing cool air from circulating throughout the home. Contact a HVAC professional for heat pump repair in this case.


Heat pump won’t start
Power issues can cause the heat pump to completely stop working. If this happens, neither warm nor cold air will be distributed throughout the home. To address this, follow these three simple steps:

  • Check the circuit breaker and ensure it’s set correctly.
  • Make sure both the indoor and outdoor units are turned on.
  • Check if the reset button on the outdoor unit is tripped. If it is, press the button once to reactivate the system.
  • If not, call a professional for assistance.


Frozen system

A frozen heat pump will hinder the normal heat transfer process. Here are some methods to resolve this issue:
Seal any system leaks that are causing refrigerant to escape.

  • If the current air filters are dirty, install new ones.
  • Clean all dirty coils.
  • To prevent future issues, clean the coils regularly and replace the air filters every few months.

Blower fan malfunction

If your heat pump isn’t cooling your living areas, the root of the problem might be a faulty blower fan in the system. The system is providing cold air, but without a properly functioning blower fan, the cold air won’t circulate throughout the home. If you encounter this problem, ensure the thermostat is set to “auto.” If the system is set to “auto” but the cold air still isn’t circulating, seek professional help.

When the hot summer arrives, cool air is essential. If your heat pump isn’t cooling, follow these troubleshooting methods:


Check the power
The first troubleshooting tip is like tech’s “unplug and plug back in,” but for your heat pump. If the pump isn’t starting at all, even though the power is on, it could be due to a tripped circuit. Go to the circuit breaker and ensure all switches are in the “on” position.

In many cases, the outdoor and indoor heat pump units are connected to different circuit breakers, so be sure to check all the breakers if any of them are off. If one of the switches is off, turn it back on and see if it resolves the issue.


Adjust the thermostat
Set the thermostat to “cool” or “auto.” If set to “auto,” check the heat pump temperature setting to ensure it’s cool enough for the pump to blow cold air. For example, if you set the thermostat to keep the indoor air at 72 degrees, and the outdoor temperature is also around 72 degrees, your heat pump might not blow cold air because it doesn’t need to further cool your house.

If the thermostat doesn’t turn on at all or doesn’t function properly after lowering the temperature, try replacing the batteries. If it still doesn’t work properly, call a local HVAC repair technician for inspection, as you might have an electrical issue.


Check the air filters
Dirty air filters are a common issue with heat pumps. Over time, the heat pump’s air filters naturally collect dust, debris, and other particles, which can clog them and inhibit the airflow. Luckily, this is a very simple fix. Just take off the air filters and check them. If they look dirty, rinse them with warm water or replace them with new ones, depending on the type of filter you have (reusable vs. disposable).


Test the reversing valve
The heat pump’s reversing valve switches the movement of the refrigerant to allow air to flow in and out of your home. Fortunately, you don’t need to know where the valve is or even what it looks like to test if it’s working properly.


First, set the thermostat to heating mode. If the heat pump blows warm air when heating mode is on, but doesn’t blow cold air when cooling mode is on, then you may need a new reversing valve to fix the issue. Unless you have HVAC expertise, call a professional to replace the valve.


Check your ductwork system
A damaged ductwork system can cause leaks, allowing air to escape before cooling the house. Go to the attic or basement and visually inspect any exposed ductwork, paying close attention to joints and seams, and look for any damages, such as holes or disconnected sections. You should also look for signs of mold or rust, which might indicate leaks. If you find any of these issues, call a professional.


Check the outdoor unit
If the outdoor unit connected to the heat pump is frozen, it won’t effectively blow cold air. Therefore, go outside and check if your equipment has frost or ice. If you notice any signs of freezing, turn off the equipment. While dirty filters or clogged ducts might cause icing, if both of these areas are clean, you should call professionals for help, as your valve, motor, or fan might be damaged.


Debris and vegetation around the outdoor unit can also obstruct cold airflow, so be sure to regularly clear any debris that could affect its performance.


Call professionals to check refrigerant levels
Leakage, freezing, and regular wear and tear can reduce the heat pump’s refrigerant levels. When the refrigerant is too low, it obstructs cold airflow and causes other issues.

Using refrigerant can be dangerous, so don’t attempt to resolve this issue yourself. Checking the refrigerant level requires specialized tools and expertise, meaning it’s a job best suited for professionals (not DIYers).


7 major components of a heat pump system

The heat pump system consists of the following 7 major components:


Outdoor unit
The outdoor unit captures and stores warm and cold air. It contains the condenser coil and the compressor.


Air handler
The air handler efficiently distributes air throughout your home and contains the evaporator coil, blower fan motor, and electric heater.


An emergency electric heater is used to provide heating for homes that are not sufficiently heated by the heat pump alone. The heater consists of the same components as the air handler.


A refrigerant, a liquid substance, flows throughout the entire system to absorb or release heat. If your heat pump isn’t blowing cold air in your living spaces, it might indicate a refrigerant leak.


The compressor distributes the refrigerant to the evaporator coil in the air handler. This component includes the reversing valve, fan, motor, defrost control, and electrical components.


Reversing valve
The reversing valve allows the air to flow in and out of your home by switching the movement of the refrigerant. When the valve is open, the airflow happens, but when it’s closed, the airflow stops.


Expansion valve
Without the expansion valve, air conditioning wouldn’t exist. It controls the amount and speed at which the refrigerant flows through the heat pump system.

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Heat pump maintenance tips

To prevent future issues with your heat pump not cooling, you can take the following steps throughout the year. These maintenance tips will keep your pump working longer:

  • Change or clean your heat pump’s filters every one to three months.
  • Keep the outdoor unit clear from vegetation and other debris.
  • Clear any obstacles on indoor air vents, such as furniture.
  • Regularly check for any signs of damage in the ductwork system.
  • Hire a local heat pump service company to inspect your pump and perform maintenance at least once a year.


DIY vs. Hiring Professionals

Heating, ventilation, and air conditioning (HVAC) systems have many complex components, and dealing with some of them can be hazardous if you’re not a trained professional (such as toxic refrigerants). Heat pump repair done by professionals usually costs around $200 or less. If the issue becomes severe enough to require replacing an entire part or the entire unit, you might end up paying more (thousands of dollars) eventually.


In some cases, fixing the heat pump may only involve cleaning or replacing filters, changing thermostat batteries, or clearing indoor air vents or outdoor units from obstacles. For most homeowners, these issues can be easily and safely addressed on their own.


However, if you’ve followed these troubleshooting steps and are still experiencing issues with your heat pump not cooling, then it’s best to call an HVAC technician. They will have the tools and expertise needed to properly diagnose and resolve the problem before it becomes a bigger issue.



A malfunctioning heat pump can be a nuisance, especially during hot summer months when you rely on it to provide cool air. By following the troubleshooting steps mentioned above, you can identify common issues and possibly resolve them yourself. Remember to conduct regular maintenance on your heat pump to keep it running efficiently and effectively. However, if you encounter complex or potentially dangerous problems, don’t hesitate to seek professional help from HVAC experts. With proper care and timely repairs, your heat pump will keep you comfortable throughout the seasons.

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