Heat Pump Blowing Cold Air| What Are the Causes and How to Fix Them?

I know how frustrating it can be when the outdoor temperature is frigid, and at this time, your heating pump starts blowing cold air. As its name suggests, the primary purpose of a heat pump is to blow hot air. As an HVAC Expert, many people asked me, “Why my heat pump blowing cold air?”.

For Your Information!
Your heat pump blowing cold air could be a simple thermostat glitch – check settings before diving into complex fixes!


Well, in this case, there must be some issues with your heating pump, or it’s just your assumption. To solve these issues, I have compiled an in-depth guide to finding heat pump problems, why heat pumps blow cold air in summer and winter, and why heat pump maintenance is essential.

Before discussing the causes and solutions of heat pumps blowing cold air, we need to clarify two scenarios that can happen when you encounter this issue. These scenarios are:

  1. The heat pump is blowing cold air.
  2. The customer thinks the heat pump is blowing cold air.

The first scenario occurs when the heat pump blows cold air, implying that the air from the vents is colder than desired. This could indicate a heat pump problem, such as a malfunction, a leak, or a blockage. This issue necessitates rapid attention and action because it can impact your comfort, safety, and the system’s performance and efficiency. You can also read our in-depth guide on the Benefits of Geothermal Heat Pumps.

The second scenario occurs when the air feels cold due to the body’s sensitivity, not a malfunction in the heat pump. To address this, explain the heat pump operation to the customer, emphasizing that a heat pump releases cooler air than a furnace. For example, on a 35-degree day, the air may be 92 degreesdropping to 85 degrees on a 20-degree day. Despite this, the air remains warmer than the indoor temperature, effectively heating the house. Heat pumps emit less heat than furnaces but over more extended periods. Before service, measure the air temperature with a thermometer. If there’s no difference between the return and supply temperatures, it indicates a problem.

There are many possible reasons to understand why your heat pump is blowing cold air, such as:

Heat Pump Is in Defrost Mode

Heat pumps may blow cold air during defrost mode due to ice or frost build-up on the outdoor unit in winter. However, defrost mode is standard and crucial for preventing system damage. Problems with the defrost mode can impact the heat pump’s performance, so it’s vital to seek professional help for diagnosis and repair.

Heat pumps extract heat from your home’s air to keep you comfortable. In winter, ice on the outdoor unit can reduce efficiency. Maintain two to three feet of clearance around the unit to prevent this. If you encounter defrost mode issues, consult professionals for diagnosis and repair to ensure optimal system functionality.

Don’t forget to learn more about Heat Pump vs VRF

Dirty or Clogged Filter

A common cause of a heat pump blowing cold air is a dirty or clogged filter, impeding airflow and heat transfer. The filter removes dust, dirt, pollen, and particles, enhancing air quality and system efficiency. Over time, a dirty filter increases energy consumption and system wear. The solution is regular cleaning or replacement, depending on your heat pump and filter type. A clogged HVAC filter forces unfiltered air into the system, settling on components like evaporator and condenser coils and impairing function. Replacing a dirty filter when needed helps maintain proper heat pump operation, especially for parts vulnerable to damage.

Wrong Thermostat Settings

Your heat pump may be blowing cold air due to incorrect thermostat settings. The thermostat controls the temperature and operation of the heat pump. The correct thermostat settings are crucial for the heat pump as they determine the desired temperature and mode of the system. However, the settings can sometimes be inappropriate or incorrect, leading to the heat pump blowing cold air. Some examples of incorrect thermostat settings include:

  • The thermostat is set to cool instead of heat
  • The thermostat is set to fan only instead of auto
  • The thermostat is set to a lower temperature than the room temperature
  • The thermostat is set to emergency heat instead of normal heat

Refrigerant Leaks

Another potential reason your heat pump blows cold air is the refrigerant leaking. The refrigerant is a fluid that transfers heat from one place to another in the heat pump. The refrigerant is essential for the heat pump, enabling it to absorb heat from the outside air, the ground, or the water and release it inside your home, or vice versa. However, sometimes the refrigerant can leak from the system due to various reasons, such as:

  • A puncture or a crack in the refrigerant lines
  • A loose or faulty connection in the refrigerant fittings
  • A worn or damaged seal in the refrigerant valves
  • Corrosion or rust in the refrigerant coils

A Faulty Reversing Valve

Heat pumps blowing cold air could be due to a faulty reversing valve. This valve changes the refrigerant flow direction, allowing the heat pump to switch between heating and cooling modes. If the valve fails or gets stuck, it can cause the heat pump to blow cold air, such as:

  • The reversing valve is stuck in cooling mode, which means the heat pump is cooling the air instead of heating it
  • The reversing valve is stuck in the middle, which means the heat pump is not heating or cooling the air properly

Repairing or replacing the reversing valve can cost $300 and $600, depending on your heat pump’s valve type and model.

You can also learn more about Types Of Furnace Ignitors: An In-Depth Guide

System Needs Maintenance Services

Another reason why your heat pump is blowing cold air is that the system needs maintenance services. The system needs maintenance services to keep it in good condition and to prevent any problems or issues from occurring or worsening. The system needs maintenance services such as:

  • Cleaning the indoor and outdoor units
  • Lubricating the moving parts
  • Checking the electrical components
  • Inspecting the refrigerant lines and coils
  • Testing the thermostat and the sensors
  • Adjusting the settings and the controls

These services can improve the performance and efficiency of the system, as well as your comfort and convenience. It can cost between $100-$300 on average.

A heat pump is a device that can heat or cool your home by transferring heat from one place to another. However, like any other appliance, it needs regular maintenance to function correctly and avoid breakdowns. By scheduling maintenance checks at least once a year, you can ensure that your heat pump is in good condition and detect any issues before they become serious. This can save you money on expensive repairs and extend the life of your heat pump. According to Forbes, heat pump maintenance service and repairs range from around $150 to $1,950.

Additionally, regular maintenance can improve the efficiency and performance of your heat pump, ensuring that your home stays comfortable throughout the year.

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