Heat Pump Not Heating? Here Are 7 Reasons It's Blowing Cold Air

Arizona homes typically use heat pump systems to cool and heat their home year-round. These systems are great for climates that rarely ever experience freezing temperatures. Heat pumps lose some efficiency as the outdoor temperature drops, because instead of producing heat, they transfer heat from the outside air into your home. Phoenix winters rarely get cold enough for that to matter. 

During the summer months, this process works in reverse, removing heat from the home, so it stays cool. As colder weather comes in and you switch your heat pump for heat generation, your system may act up leaving you with cool air. Below we cover the seven most common reasons a heat pump would not be properly heating and help you identify normal operation versus issues that require attention.

Normal: Defrost Mode

While your outdoor unit is transferring heat to your home, it's also enduring the cold weather. When key components inside the outdoor unit have a buildup of frost or ice, the system is smart enough to power its defrost mode. When this is activated, it sends heat to the outdoor unit which leaves the inside of your home feeling cooler than usual. This process is normal and brief. Once the ice is cleared, the system should return to delivering heat inside your home. If the heat pump does not return to heating your home, then it's recommended to call a professional HVAC technician to check the system.

Side Note: Some heat pumps are set up with auxiliary heat. When the system is running its defrost mode, your auxiliary heat or back up heat will kick in to maintain some warmth indoors. The auxiliary heat turns on and heats the air coming out of the vents. Once the ice has been sufficiently melted, your heat pump will resume normal operation, and your auxiliary heat will turn off.

Normal: Heat Runs at Lower Temperature

Unlike furnaces that produce heat and the air feels hot, heat pumps move heat from the outside to the inside and vice versa which naturally makes them deliver milder heat at around 85°F to 95°F. By comparison, a gas furnace delivers noticeably hotter air, so a temperature discrepancy like that is normal. Of course, you should still feel warmth coming into your home. If your heat pump is set to heat mode and the air feels very cool, then schedule a heat pump service visit with an HVAC technician.

Issue: Fan is Set to On

If your heat pump is blowing cold air in the winter, check your thermostat and review your current settings. You need to ensure that your thermostat is set to "Heat" and the fan is set to "AUTO." If your fan setting is set to "On," your heat pump will blow air, whether heated or not. When set to "AUTO", your heat pump will only blow air when heated. If your fan runs continuously, it will blow unheated room air through the vents between heating cycles. Because moving air creates a wind-chill effect, it will feel like cold air is blowing on you, making your home feel less comfortable. Check your thermostat settings and review your fan settings. If your fan is already set to AUTO, then give an HVAC technician a call for service.

Issue: Dirty Air Filters

A dirty or clogged air filter restricts airflow, which prevents the heat pump from properly distributing warm air throughout your home creating climate discomfort during the winter season. Additionally, this restricted airflow strains the outdoor unit causing component failure or ice buildup. As with any HVAC system, keeping your air filters clean is essential, which is particularly important for heat pumps. If you experience any problems with your heat pump's performance, take a look at your air filters and their current condition. If they look dirty, replace them with new ones to see if that resolves the problem. You can also schedule routine maintenance with George Brazil, so the system is ready for peak heating use.

Issue: Stuck Reversing Valve

The reversing valve is critical in switching your heat pump from cooling to heating mode. If the valve malfunctions, your heat pump may remain in cooling mode, resulting in cold air blowing out of the vents instead of warm air. To resolve this issue, you should seek the assistance of a professional technician who can inspect your system and make the necessary repairs.

Issue: Low Refrigerant

Your heat pump pulls heat into your home through refrigerant. If your refrigerant levels are low, your heat pump will struggle to bring enough heat into your home to warm it properly. An HVAC technician will need to stop by to evaluate your refrigerant levels to determine if the system needs to be recharged. If levels are low, there may be a leak that will need to be fixed by a licensed professional.

Issue: Outdoor Unit is Blocked

Since your heat pump pulls heat from the air outside into your home it literally needs room to breathe. If the airflow to the outdoor unit is blocked by debris such as leaves, grass, foreign objects, or blockages like fences or barriers, its ability to bring in warm air and push out cool air is obstructed. To remedy this, clean your outdoor unit and remove any blockages that could prevent proper airflow.

Stay Proactive with Heat Pump Maintenance with George Brazil

If you are experiencing issues with your heat pump not heating your home, call the expert HVAC technicians at George Brazil to conduct quality heat pump repair services. After our team fixes your heat pump's heating issue, set up routine maintenance with us so we can check the system before peak usage. Our Worry-Free program brings an expert set of eyes to the system ahead of each season, and you get a system report card on every visit. Schedule your heat pump repair and maintenance with George Brazil today!