Short answer
An AC coil freezes when not enough warm air crosses it or when refrigerant is low. Turn the cooling off, run the fan to thaw the ice, replace the filter, and call a technician if it freezes again.
Rather have a licensed tech look at it?
Call (702) 602-9362How to thaw it
Thawing usually takes one to several hours.
- Set the thermostat to Off
- Set the fan to On to move air across the coil
- Place towels near the indoor unit for meltwater
- Replace the filter
Common causes
Airflow and refrigerant are the two main causes.
- Dirty filter or blocked return vents
- Dirty evaporator coil
- Failing blower motor or capacitor
- Low refrigerant from a leak
- Closed supply registers in many rooms
Why it matters
Liquid refrigerant can return to the compressor when the coil is frozen, which can damage it. Meltwater can also overflow the drain pan, especially on attic units common in two-story Las Vegas homes.
Questions
Can I use a hair dryer to thaw my AC coil?
It isn't recommended. Running the fan is safer and avoids damaging the coil or getting heat near wiring.
Why does my AC freeze at night?
At night, lower indoor temperatures and humidity can push an already marginal system into freezing, often because of low airflow or low refrigerant.
This guide is general information for Nevada homeowners. For anything involving gas, refrigerant or electrical parts, use a licensed HVAC contractor.