4 Reasons Your Heat Pump Is Blowing Cold Air Even in Heating Mode

Millions of American households use heating and air conditioning systems outfitted with heat pumps to keep them warm and comfortable. When used correctly, they’re durable and energy-efficient heating options that come incredibly handy during frigid winter months. Now that the winter season is well underway, people use their heating solutions more than ever, requiring maintenance and regular inspections to ensure that nothing goes wrong.

Problems with your heating system can be incredibly frustrating to deal with when it happens in the middle of subzero temperatures, so you’ll need to be on the lookout for any potential issues. One of the most common problems you may encounter is when your heat pump blows cold air even when it’s on heating mode. Here are four possible reasons your heat pump may be behaving oddly and what you can do to resolve the issue: 

Freezing temperatures mean almost everything will be covered in frost, and your heat pump is no different. While operating normally, it is still susceptible to developing ice or frost on its outdoor coils, especially when your heat pump system is worn out and overworked. It often manifests as ice freezing up, making your unit produce colder air. When your heat pump detects ice build-up, it switches into a cooling mode to undo the refrigerant’s flow inside the coils. In this mode, the hot refrigerant flows through the exterior coils, melting the ice build-up and ultimately warming up the system.

However, if your heat pump is frozen, you should call HVAC repair technicians right away. These certified professionals know the ins and outs of your unit, which means they’ll know the best, most efficient ways to resolve the problem. Fixing the problem yourself may cause further damage to your unit, requiring an expensive replacement. It’s also a reason to have your HVAC system inspected and regularly maintained to ensure that it doesn’t suffer from irreversible damage.

Other causes that lead to a frozen heat pump include faulty defrost controls, a defective defrost relay, malfunctioning outdoor fan motors, sticking reversing valve, damaged or faulty defrost thermostat or sensors, and low refrigerant levels. If you find your heat pump covered in frost, make sure to turn off your system and call an HVAC technician right away. While waiting for them, you can inspect your HVAC unit’s air filter to check if it’s clogged with dust or damaged in any way. You can also remove any build-up of snow, dirt, grass, leaves, and other debris that can interrupt your unit’s airflow or outdoor coil. 

Unbeknownst to some homeowners, some heat pumps function as reverse air conditioners. They create heat by sucking in cold air, converting it to hot air, then distribute it throughout your home. This functionality makes it possible for specific heat pump models to work with heated air when shifting into defrost mode.

This handy HVAC feature can be handy when you cannot easily access your outdoor unit to inspect it. Defrost mode allows your HVAC system to melt down ice accumulation on your outdoor unit, allowing you to access it. Otherwise, attempting to maneuver a frozen unit can ultimately damage it. If you observe that your heat pump is in defrost mode, make sure to switch it to heating mode, as it won’t distribute hot air until it has finished its defrost cycle.

Although people sometimes confuse the two together, it’s important to remember that heat pumps are different from furnaces. Furnaces blow out sweltering hot air, making approaching the furnace dangerous. However, heat pumps blow out warm enough air that usually measures around 85 to 90 degrees. Although that air isn’t hot, it’s much warmer than your surroundings. Due to your body’s temperature, you may think that the air your heat pump is blowing is cold when really, it’s quite warm!

Most of the time, thermostat settings are configured to 68 degrees. You can verify your heat pump’s air temperature by inspecting your thermostat every half hour after turning it on and observing any temperature changes. Your indoor temperature should be roughly 85 to 90 degrees within an hour or slightly longer. However, if it stays at a much lower temperature, you’ll want to call a heat pump systems technician to inspect the problem.

If you’ve thoroughly inspected your heat pump’s user guide and performed all the troubleshooting steps and your heat pump is still blowing cold air, that may be a sign that something is critically wrong with your system. A continuously malfunctioning heat pump is difficult to repair by yourself and requires expertise, so you’ll need to call HVAC repair technicians to inspect the problem. Remember that you may need to replace some components in your system to get it up and running again, so make sure you have everything in need to survive a few days with much less heating. 

Consulting a technician will inform you of the most efficient and reliable ways to resolve the problem, especially if you’re in for a biting-cold winter. Once everything is repaired and resolved, make sure to conduct regular inspections on your HVAC system to ensure that sudden breakdowns or problems don’t compromise your home’s comfort.


Heat pump systems are convenient to have when battling cold temperatures. However, when these break down in the most inopportune times, it can be very inconvenient and difficult to resolve. By keeping these four reasons in mind and calling local technicians to inspect your HVAC system regularly, you’ll enjoy a cozy and comfortable winter season!

If you need unbeatable HVAC and furnace repair, Air Unlimited Heating and Cooling is the one to call. We offer AC service and tune-up in Liberty, providing prompt and detail-oriented work to homeowners in Liberty and the surrounding areas. We’ve been BBB-accredited since 2019 and hold an A+ rating, and our technicians are all licensed, insured, and NATE-certified. Contact us today to schedule an inspection or repair!