While it seems ironic that when temperatures soar during summer months in Kansas City your air conditioner can freeze over, it does happen. Why does this happen, and what should you do if you find your air conditioner has frozen up? At Schomburg Heating & Cooling, we’ve got a few pointers for you.

Why do air conditioners freeze?

There are several issues that may result in your air conditioner freezing over. These include:

The air filter is clogged. Sufficient hot air must move over the evaporator to prevent freezing over; a clogged air filter can result in reduced airflow, and thus less air being delivered to the evaporator coil.

Refrigerant issues. If your refrigerant system is not sufficiently charged, the levels of refrigerant delivered to your cooling system may be too low. The evaporator coil may become too cold when the refrigerant pressure drops below normal, which makes it possible for moisture present in the air around the coil to accumulate and freeze.

Thermostat issues. An air conditioner that runs constantly (such as a night, when you may not notice) can cause your air conditioner to freeze up. This also results in wasted energy, and higher utility bills.

Inadequate fan speed. Air should flow at the correct speed over the evaporator coil; otherwise, if the blower motor is sending air over at a speed that’s too low, it may result in a frozen A/C.

Registers that are closed or blocked. When registers are blocked by furnishings or rugs, or you have closed off registers in rooms that are rarely used, it can restrict airflow although you don’t realize it. Shutting off more than 1/4 of the registers in your home can result in your air conditioner freezing over.

Window A/C unit not tilted properly. Window air conditioners should be tilted slightly down on the outside portion, so that water can drain from the drainage hole rather than remaining inside the unit, where it may freeze and cause you air conditioner to shut down.

Drainage issues. A clogged drain can result in freezing; one of the functions of an evaporator coil is to remove excess moisture from the air inside your home. This excess moisture collects on the coils before dripping into a condensate pan, which drains to the outdoors. Water that backs up due to a clog can result in freezing the entire distance to the evaporator coil, causing the problem to become even worse due to the fact that the ice blocks the drain even more.

What should you do in the event your air conditioner freezes?

  • First, turn off your A/C to reduce the risk of damage to the compressor
  • Locate the condensate drain and check to ensure it isn’t backed up
  • A blow dryer used on the evaporator coil can help speed up the thawing process; in addition, run your A/C on fan mode without the compressor to facilitate thawing
  • Suctioning out water using a wet-dry shop vac after opening the ductwork may be effective; the shop vac will suction out water as the ice melts
  • When the ice has melted and you’re sure the condensate pan is draining properly, switch the A/C back on. Your unit should begin working to cool your home quickly.

There are many things Kansas City homeowners can do when the air conditioner freezes, however if you try all of the recommendations above with no success, call your air conditioning contractor for further assistance. It could be that your thermostat needs to be adjusted, fan speed increased, refrigerant level checked, or even a repair needed to have your A/C working efficiently again. At Schomburg Heating & Cooling, you can rest assured your home will be cool, comfortable, and energy efficient once again!