Why Is My Heat Pump Freezing Up?

Our team at AA Air Company regularly gets calls about frozen heat pumps. Though common, a heat pump freeze-up usually means your system’s components are not working correctly, or there’s an extraordinary environmental factor causing the issue. Sometimes you can fix it yourself. But oftentimes, you will need to call a heating, ventilation, and air conditioning (HVAC) professional, like us, as the problem may require a part replacement or complex repair.

Heat Pump Brain Freeze

To help sort things out, here are the six usual suspects causing heat pumps to freeze up:

1. Clogged Air Filter

When air filters are left to collect particles for too long, they become clogged. This hinders airflow, trapping moisture. Dust, pet dander, and smoke are just a few examples of things that can clog your filter. 

The National Air Filter Association (NAFA) recommends changing your system’s filter as soon as it is loaded with dust and debris. How quickly your filter becomes clogged depends on many factors in your home. At AA Air Company, we recommend switching to a new filter, at a minimum, every three months. However, if you have pets, smokers, or a situation creating dust (remodeling, carpet change-out, etc.) you should change the filter more often.

Try replacing your air filter, then running your unit’s heat setting to melt the ice. If this does not clear the problem, contact one of our trained experts to come out to help.

2. Low or Empty Refrigerant

If your heat pump is low on refrigerant, it may be leaking. This can be from of a weakened solder joint, a failed valve, unsecured fittings, holes that develop over time, etc. Also, when a component rubs against the refrigerant tank over time, it could eventually puncture it, leading to a freeze-up. 

When the pipes start rattling, play it safe and power down your heat pump. Then contact one of our HVAC professionals for immediate inspection.

3. Filthy Evaporator Coil

Refrigerant flows through your heat pump’s evaporator coil. It transports heat into your Knoxville home during cool weather, and pulls it out during hot weather. When the coil becomes dirty, its ability to transfer heat is impaired. Compromised airflow can lead to a freeze-up. 

If you notice ice on your coils, power down your heat pump. Then gently pour warm water over the coils to melt the ice. If your coils freeze back up, call one of our HVAC team members.

4. Faulty Blower Motor

If your blower motor is not up to speed, it can wreak havoc on your system, leading to a freeze-up.

The fan may start and stop intermittently, run at a reduced spinning cycle, or not run at all. If this is the case, have someone from AA Air Company replace it.

5. Dirty Fan Blades

When the blower’s fan blades are dirty, this compromises the system’s airflow and exhaust output. Moisture may become trapped and turn into ice. If this happens, give us a call to correct it, as the fan blades are quite delicate.

6. Wintertime Neglect

Depending on your heat pump model and your Tennessee home’s geographic location, some air-source heat pumps (ASHPs) do not always operate efficiently in colder temperatures. Our system designers are careful to match the unit to the home and it’s location. However, if we did not install your unit and you have questions, please check with one of our experts.

Also, the unit should be completely level with the ground; any tilting can cause moisture to get trapped and become frozen. Again, talk to our HVAC professionals if you believe your heat pump is not level.

Finally, an environment that constantly covers your unit in ice or heavy snow can be problematic to the function of your system. Check for leaking gutters or other water sources that can drip on the unit and lead to ice build-up. Also check your system during/after snowstorms to be sure that it is staying clear of heavy build-up. 

Always check for ice and snow accumulation around or on your unit, and clear it to prevent further issues. Be sure not to try to chip off the snow or ice using any type of tool, because you can easily damage the heat pump. If a normal thaw or a simple brushing is not enough, you’ll want to turn off your unit and then pour warm (not hot) water over it to melt the snow and ice. Once the unit is clear of snow and ice, turn it back on.

If you are not sure what the problem is, and why your unit has frozen up, please do not hesitate to call us to come out, inspect your system, and properly resolve the issue. We are here to help!

Contact Us With Any Heat Pump Issues

Experiencing a frozen heat pump? Our AA Air Company team of experienced HVAC professionals is just around the corner in Knoxville, TN, to assist you. Call us today at 865-213-1354 or request service online if you need a repair or are interested in upgrading your current system.