Should You Turn Off Your AC If It's Not Cooling?

Short answerIf you see ice on the coils or lines, yes. Trane says to turn the system off and contact an HVAC professional. If nothing is frozen, it doesn't say you must shut it off: check the thermostat and filter first, then call if it still isn't cooling. We'd also turn it off for burning smells, loud noises or tripped breakers.

What this costs

Our national estimates, not quotes.
Option	Job	Low	High
Replace	AC Replacement	$3,800	$9,050

Quick checks before you call

Thermostat set to cool, below the room temperature, and the fan on Auto. Trane lists all of these.
Blank screen: replace the batteries, also from Trane.
Filter: replace a clogged one. Trane and DOE both list this cause.

When turning it off makes sense

We recommend leaving the problem to a technician if it could be refrigerant. ENERGY STAR says the wrong refrigerant level makes a system less efficient and shortens its life.

You see ice or frost on the coil or refrigerant lines. Trane says to shut it down and call.
You smell burning or hear grinding or banging. That's our advice, and it's about avoiding more damage.
The breaker keeps tripping. That's our advice too: don't keep resetting it.

If it's only a little weak

In our view, a system that runs but cools poorly isn't always an emergency. On a very hot day, we expect it may just be working hard. Sources we read didn't say that keeping it running does damage in every case, so use your judgment and call a technician if it doesn't improve after the basic checks.

AC Not Cooling? What to Check Before You Call

Common questions

How long should I leave it off if it froze?

Trane's page doesn't give a time. Our guide on a frozen AC covers thawing. We recommend calling an HVAC technician to find the cause, because we expect it can freeze again.

Can I run just the fan?

Trane doesn't address that on this page. Ask your technician when you call, since the right move depends on what's wrong.