Ice on Your AC in a Knoxville Summer? Here's Why

It feels wrong: a 95-degree afternoon in East Tennessee, and your air conditioner is wearing a coat of ice. But frozen coils are one of the most common mid-summer calls we get across Knoxville — and the ice itself is only the symptom. Keep running a frozen system and you can liquid-lock the compressor, turning a modest repair into the most expensive one your system has.

Two Causes, One Result

A coil freezes when its temperature drops below freezing, and that happens for one of two reasons. The first is restricted airflow — a filter choked with valley pollen, a blower wheel matted with dust, too many closed vents. Without enough warm air crossing the coil, it gets colder and colder until condensation turns to ice. The second is low refrigerant from a leak: less refrigerant means lower pressure, lower pressure means a colder coil, and the same ice forms.

Pollen-season filters cause most of the airflow freezes we see in Knox County. Refrigerant leaks cause the rest — and leaks don't fix themselves.

What To Do Right Now

• Turn the AC off at the thermostat — running it frozen risks the compressor
• Switch the fan to ON to help the ice melt faster
• Check and replace the filter while you wait
• Put towels near the air handler — a frozen coil melts into a lot of water

If a clean filter doesn't solve it, the cause is almost certainly a refrigerant leak, and that's sealed-system work for a licensed technician. We'll find the leak, repair it properly, and recharge to spec — not just top it off and leave you frozen again in August.