Troubleshooting a central AC
There's ice on the AC. Turn it off first.
Running a frozen system can do real damage. Shut it off, let it thaw, and use the time to check what usually causes it.
In this order
Stop it, thaw it, then find out why it froze
This page starts on red on purpose: the first move is to stop the AC. The checks come while it thaws.
Stop, and call
Do this now
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Switch the thermostat from Cool to Off
Running the system with a frozen coil can cause major damage to it, so the AC goes off before anything else.
Source: Trane, My AC Evaporator Coil Is Frozen, checked 2026-10-22.
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Leave the ice alone
Don't chip at it. Let it melt on its own.
Source: Trane, My AC Evaporator Coil Is Frozen, checked 2026-10-22.
Safe to check yourself
While it thaws
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Source: American Standard, Frozen Evaporator Coil? Don't Panic, checked 2026-10-22.
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Source: Trane, My AC Evaporator Coil Is Frozen, checked 2026-10-22.
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Source: Trane, My AC Evaporator Coil Is Frozen, checked 2026-10-22.
Worth a visit from us
What it usually means
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Low refrigerant, which means a leak
A system only runs low if it leaks, or if it was charged wrong when it was installed.
What we do: We test for the leak and repair it before we recharge, so it isn't a refill every summer.
Source: Trane, My AC Evaporator Coil Is Frozen, checked 2026-10-22.
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A dirty indoor coil
Dust and debris on the coil cut the air moving across it, and it frosts over.
What we do: We clean the coil and check the blower while we're there.
Source: Trane, AC Not Turning On, checked 2026-10-22.
Tell us what it's doing. We'll take it from there.
Call and describe the problem: the noise, the smell, the room that never warms up. Or book a visit online.
