Heat Pump Isn't Cycling Properly? Clean Your Air Handler's Evaporator Coil

If your heat pump won't cycle off and on properly, you may think that it's broken or damaged in some way. But that's not always the case. Sometimes, problems can occur in other areas of the cooling system that affect the performance of your heat pump, including the air handler or indoor unit. The easiest thing to check and change first is the air handler's air filter. If the air filter is clogged or covered with dirt and dust, the heat pump won't cycle off and on properly. However, if you change the air filter and the heat pump still won't cycle correctly, clean the air handler's evaporator coil.

How Does a Dirty Evaporator Coil Affect Your Heat Pump?

One of the most common reasons for a heat pump that doesn't cycle off and on is a blocked evaporator coil. If dirt, dust, ice, or mold covers the evaporator coil's surface, air can't flow through it. As a result, your heat pump can't send cool air through to the home. 

Your heat pump can eventually break down and require servicing from a professional HVAC technician. But if you feel comfortable or confident, you can clean the evaporator coil yourself to see if it improves your heat pump's performance. 

Can You Clean the Evaporator Coil Yourself?

Before you clean your evaporator coil, turn off the heat pump's power source at the breaker box or on the thermostat. You want to avoid electrical shocks during the cleaning.

Next, remove the covering over the evaporator coil and set it aside. The evaporator coil is the large, triangular-shaped apparatus found near the opening of the air handler. Tiny, thin fins cover the entire surface of the coil, so be careful when cleaning them. The metal fins can cut your fingers, as well as break under pressure. 

After you remove the unit's covering and expose the evaporator coil, follow these steps below:

• Place a tarp beneath the air handler to protect your flooring from water and debris during the cleaning.
• Use a soft-bristled toothbrush and warm, soapy water to gently remove any residue you see on the evaporator coil's fins. Avoid applying pressure or using force on the fins, even if some areas of the coil seem too clogged or covered with debris. 
• Use a spray bottle filled with 1 cup of white vinegar and several cups of warm water to rinse the stubborn areas. If possible, soak the areas thoroughly with the solution for 15 minutes to see if they clear up.

You can place a small fan in front of the evaporator coil to help it dry. Otherwise, wait at least 30 minutes for the water on the coil dries on its own. Replace the cover and turn the unit back on. If the heat pump cycles off and on, you fixed the problem. If not, then contact your HVAC contractor and have your heat pump inspected.

If you don't feel comfortable about cleaning your evaporator coil yourself, be sure to schedule an appointment with your HVAC technician (such as D & R Service Inc) right away