Keep Your Cool: How To Unfreeze Air Conditioner Coils

Posted on: 4 August 2015

If your air conditioner isn't cooling correctly, it could be because of frozen coils. Unlike refrigerators and freezers, air conditioners do not have a thaw cycle to eliminate ice accumulation. As soon as you notice the problem, shut off the unit since frozen coils can place strain on the compressor. Here are some tips to repair frozen air conditioner coils.

Thaw the Unit

Don't be tempted to remove the ice by hand since the fins and coils could easily get bent. Though you are advised to turn the unit off, leave the fan unit running to speed up thawing by circulating warm air over the evaporator. If the unit doesn't shut off in two minutes, it usually means you have a faulty contactor.

You will have to turn it off at the breaker that controls it. If your unit has a heat pump mode, set it on heat mode to move hot refrigerant through the coil. Another way to thaw the unit is using a hair dryer on the lowest setting. It could take several hours to 24 hours depending on the humidity and method you use to thaw the ice. After the coils have thawed, clean up excess water on the floor and moisture on the coils.

Clean the Filters

Frozen coils are likely caused by dirty or clogged air filters which restricts air flow. If you don't have washable filters, discard the dirty set and replace them with new ones. To clean washable filters, wash the screen with a hose, but don't use soap unless  the manufacturer suggests it and try the air conditioner again. 

Measure Refrigerant Levels

Low levels of refrigerant, the substance that cools the air before it enters the space, could cause coils to freeze. One of the first signs of low refrigerant levels is leaks. Measure refrigerant levels with a  test kit available from home improvement stores. However, refrigerant can freeze skin so it is advised to contact an HVAC professional to refill it if you aren't' skilled with using the substance.

Check for Malfunctioning Blower and Blocked Return Grills

A malfunctioning blower will restrict the air flow to the coils causing the coils to freeze. Even when filters are clean, the blower may still get the fins dirty. If you have a central air unit, inspect rooms for blocked return cold grills and remove any furniture or items blocking them. 

For more information, contact Allied Air Conditioning & Heating Corp or a similar company.