Why Does Your AC Unit Look Like Frosty The Snowman?

Snowmen are only around in the winter, so when your AC compressor starts looking like Frosty with a thick coat of snow and ice, you'd better be suspicious. Your AC unit isn't trying to usher in the winter. What it is doing is sending you a message that something's not quite right. So instead of capping it in a top hat and giving it a carrot as a nose, follow these steps to address the problem and stop it from freezing over.

Step 1: Change your filter.

Many times when an AC condenser starts getting frosty, it's because dust is accumulating in the coils. This dust holds onto any condensation that forms on the coils. With the condensation and dust present, the passing air can't effectively remove the "cold" from the coils, so they grow colder and colder, until the dust and condensation mixture freezes on them. If you change the AC filter, it will do a better job of trapping this dust before it has a chance to reach the coils.

Step 2: Clean the coils.

Once you have a new filter in place, turn your AC off and let Frosty melt. (Don't worry—he'll be back again in January on your lawn where he belongs!) Once the ice is gone, spray the dirty AC coils with a coil cleaning solution from your local home and garden store. Usually, all you do is spray the solution onto the coils and let it drop down onto a cloth or pan you've placed below. You can wipe any residue off the coils, and then turn the AC back on when they're dry. With any luck, the ice and snow shouldn't re-appear now that your coils are clean and you have a new filter.

Step 3: Monitor for additional freezing problems.

If Frosty the Snowman refuses to stay away and re-appears on your AC unit just a few days later, then it's unfortunately time to call your HVAC technician. There are a number of harder-to-solve problems that can cause the AC unit to freeze over, including:

Low Refrigerant Levels: If there's not enough refrigerant in the coils, the refrigerant may expand, causing it to super-cool and freeze the unit over. Your HVAC technician needs to top up the refrigerant since doing this yourself will often void the warranty on your unit.

Thermostat Connectivity Problems: Your thermostat may not be properly telling your AC unit when to turn on and off. If it is being triggered to run for too long, this could cause Frosty to appear. An HVAC tech from a company like Advanced Heating & Cooling may need to replace your thermostat or adjust the way it's wired into your system.