Air conditioning is one of those things that we take for granted, but if your AC won’t turn on all of a sudden, life can become miserable quickly. You need to figure out what happened so you can address the problem right away and make your home comfortable once again.

Why Your AC Won’t Turn On

Is your AC making loud noises, or worse, won’t turn on at all? We feel your pain! Luckily, we have experience dealing with these sorts of issues, and the source of the problem can usually be narrowed down to one of the following:

#1 – Circuit Breaker Tripped

What it is: The electricity in your home is controlled by one or more circuit breakers, usually located outside the house. In them, you’ll find on/off switches that control the power to each room or appliance with high power consumption like your AC.

How it fails: A power surge can cause the circuit breakers to trip, cutting off power and preventing your air conditioner from operating.

How to Diagnose: Find the correct breaker switch for your AC unit and reset it only once. Once it’s been reset, test the unit again to see if the problem’s been fixed.

ac making loud noises

Image from The Spruce

#2 – Thermostat Issues

What it is: Every air conditioner is controlled by a thermostat somewhere in your home. It needs to have power and the correct settings, otherwise, your AC won’t turn on.

How it fails: Most thermostats are battery-powered, and of course, all batteries run out of juice over time. The problem can also come down to not having your AC set to Cool, or even from not setting the temperature low enough.

How to Diagnose: Replace the batteries, check that the unit is on the Cool setting, and make sure it’s set to at least three degrees below the current room temperature.

air conditioner won't start

Image from Consumer Reports

#3 – Dirty Air Filter

What it is: Your AC uses an air filter to remove dirt and debris from the air flowing into your house.

How it fails: Over months or even years of use, your air conditioner’s filter can become clogged. If the problem becomes severe enough, the unit can freeze or stop running altogether.

How to Diagnose: Purchase a new filter for your model, replace it, and try running the air conditioner again.

a/c won't start

Image from Do It Yourself


If your air conditioner won’t start after following these steps, call Tiger Mechanical right away for the most experienced HVAC repair service in the area!