Why Is My AC Freezing Up?
A frozen AC coil is almost always caused by one of three things — and only one of them needs a technician.
By Duke Hilbert
An AC that freezes up in the middle of a Salina heat wave — ice on the indoor coil, ice on the outdoor line — is telling you it can't move enough air across the evaporator. Ninety percent of the time, one of three things is behind it.
The three causes, in order
Airflow first, refrigerant second. Almost every frozen coil we're called out on is one of these:
- Dirty air filter — restricted airflow drops evaporator temperature below freezing. Change the filter and thaw for 2-4 hours.
- Blocked return vents or closed supply registers — same effect. Rearrange furniture and open every register.
- Low refrigerant (a leak) — insufficient refrigerant causes the evaporator pressure to drop, temp drops, coil freezes. Needs a licensed tech to locate + repair + recharge.
What to do RIGHT NOW
Turn the system off — running a frozen system will damage the compressor. Run the fan only (thermostat: Cool off, Fan On) for 2-4 hours to melt the ice. Once thawed, replace the filter and test.
If the system re-freezes within 24 hours, don't run it again. Call us — you've got either a heavy airflow restriction we need to find, or a leak.
Key takeaway. Turn a frozen AC off — running it iced up damages the compressor. Melt the ice, change the filter. If it re-freezes, it's leak time.
Need a hand from a real Central Kansas technician? Call (785) 822-7550 and a Comfort Heating & Air tech will walk you through it — or request service online and we'll follow up the same business day.
Ready for comfort that cares?
Call Comfort Heating & Air in Salina — or send a request and we will follow up during business hours.