Why Your Heat Pump HVAC System Ices Up In Winter (And When To Worry)
When the temperatures drop in Colorado, the last thing you want is your heat pump covered in ice. It might look alarming, but a little frost on your outdoor unit isn’t always bad news.
However, when the ice starts to build up and doesn’t go away, that’s when it’s time to pay attention.
Why Do Heat Pumps Ice Up?
Your heat pump works by transferring heat from outside air into your home. During this process, the outdoor coil naturally gets cold. When moisture in the air comes into contact with that cold surface, it can freeze.
Normally, the system’s defrost cycle melts this frost before it becomes a problem. But if something goes wrong, the ice can start to pile up.
Common Causes Of Ice Buildup
Restricted Airflow – Airflow is crucial for a heat pump’s performance. If your air filter is clogged, vents are blocked, or debris has gathered around the outdoor unit, the system struggles to breathe. When that happens, the coils can get too cold and freeze over.
Low Refrigerant – Low refrigerant levels usually indicate a leak somewhere in the system. This reduces the heat transfer efficiency, causing the coils to get colder than they should and leading to icing.
Defrost System Malfunction – Your heat pump has a built-in defrost cycle to handle normal frost. If the sensor, control board, or reversing valve fails, the defrost cycle may never activate, allowing ice to build up quickly.
Extreme Weather – Colorado winters can be unpredictable. Freezing rain, snow, and long cold spells can all cause excessive ice on your unit, especially when temperatures stay below freezing for extended periods.
When Should You Worry?
A little frost on the outdoor coil is perfectly normal, especially in cold, humid weather. Your system will likely handle it on its own. But if you notice thick ice covering the entire unit or ice that doesn’t melt after a few hours, it’s time to take action.
First, turn the system off to prevent damage. Then, check for easy-to-fix issues like a dirty air filter or visible debris around the outdoor unit. Never try to chip the ice away yourself this can damage the coils.
Trust Your Local Colorado Experts
If the problem continues, it’s best to call a trusted HVAC professional. The team at SWAN Plumbing, Heating & Air Conditioning, INC has been helping Colorado homeowners stay warm and safe through countless winters.
From defrost system repairs to seasonal maintenance, we make sure your heat pump runs efficiently all season long.
