How to Prevent Coil Damage in Air Source Heat Pump

What You'll Need
Drain tube

An air source heat pump is a more efficient way to supply heating and cooling to your home. These work by pulling in air from outside and passing it through a coil to heat or cool the air, then forces it in to the home. The result is less money spent in utility bills, and a comfortable home environment even in extreme conditions. The coils are the most important aspect of the system, and knowing how to protect them will save a lot of time and trouble later on. Here's what you should do.

Step 1 - Defrosting Cycle

An air source heat pump will go through a defrost cycle in cold weather. This cycle keeps the coil from freezing over. Most heat pumps will have a sensor that determines when the defrost cycle needs to kick in. During the defrost cycle you should see some steam coming from the unit. To protect the coil during the defrost cycle you need to keep the sensor cleared. There is also a water drain tube that needs to stay in place. If the water isn't allowed to drain away during the defrost cycle it will sit around the coil. This could cause it to freeze if the temperature is cold enough and damage the coil.

Step 2 - Filters

Most people understand how important it is to change filters frequently to keep their system running efficiently. With an air source heat pump this is more important. If the system has to work harder you risk the coils going out prematurely. Check your filters at least once a month, and replace them as necessary. At the least you should replace them twice a year, although bimonthly replacement is recommended.

Step 3 - Keep the Area Clean

You want to keep the area around the system outdoors free of debris. Leaves and twigs can get in to the system causing damage to the coils. After heavy storms you want to check to make sure you don't have branches or other debris blocking the system. Even leaves can build up around the outside of the system restricting the airflow. This will cause more wear and tear on the coils. After you mow your yard make sure you haven't left grass clippings near the outside unit. In the fall make sure you are raking leaves frequently.

Step 4 - Inspections

If you see water puddling around the area, you should call a serviceman to inspect the unit. Puddling water can mean the drainage system isn't working properly, and excess moisture is hanging out near the coils. This can cause freezing coils in cold weather, and damage to the coil as it heats in hot weather. Keep an eye out for unusual noises, extra long cycles, or short cycling. All of these things should be inspected by an authorized service agent.