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AC PROBLEM · DIAGNOSIS GUIDE

Frozen AC Coil — What to Do Right Now

Ice on the copper line set or the indoor coil means your AC system is fighting itself. Here's what's causing it and how to fix it.

Since 1999NJ Lic #19HC0010870024/7 DispatchSame-DayNewton, NJ

Step 1 — Turn the System OFF Now

Running a frozen AC damages the compressor. Turn it off at the thermostat. Set the fan to ON to help thaw faster. Let the ice melt naturally over 4-6 hours — don't chip at it. Then replace the air filter and try again.

First Steps

Step 1: Turn the System OFF

If you see ice on the refrigerant lines outside, ice on the indoor coil, or water dripping in places it shouldn't, turn the AC off at the thermostat immediately. Running a frozen system damages the compressor — and a new compressor costs more than most of the underlying repairs.

Set the fan to ON (not AUTO) to help the ice thaw faster. Don't try to chip the ice off with anything — you'll damage the fins. Let it melt naturally over 4-6 hours.

Why It's Happening

Three Causes of a Frozen Coil

1

Restricted airflow

A dirty filter, closed registers, blocked return air, or a failing blower motor all reduce airflow over the coil, which makes it freeze. Filter is the most common culprit by a wide margin.

2

Low refrigerant

If the system is leaking refrigerant, pressure drops below normal and the remaining refrigerant gets too cold. Coil freezes. Recharging without finding the leak is a temporary fix — the leak gets bigger.

3

Faulty thermostat or sensor

If the thermostat keeps calling for cool when the indoor temp doesn't actually need it, the system runs too long and the coil freezes.

When to Call Us

When to Call Us

Replace the air filter, let the system thaw fully, then try again. If it freezes again within 24 hours, call us. Continued operation will damage the compressor.

Call (973) 948-0680 — same-day appointments available. Diagnostic fee waived when you book the repair.

27 yrs
Since 1999 in Sussex County
24/7
Real techs answer — not voicemail
NJ Lic
HVACR #19HC00108700
$0
Diagnostic fee waived when you book repair
★★★★★

Saw ice on the line set and panicked. They walked me through what to do over the phone before the tech even arrived. Fixed for under $300 — much less than I expected.”

Linda M. · Hopatcong, NJ

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A licensed technician picks up. Not a call center.

Same-day appointments in Sussex and Morris counties. 24/7 emergency dispatch — answered around the clock by a real on-call technician.

98 Morris Turnpike, Newton NJ · NJ HVACR Lic #19HC00108700 · Since 1999

At Constant Air, we specialize in delivering high-quality heating, ventilation, and air conditioning services that keep your home and business comfortable all year round.

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