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Fixing Air Conditioner Problems: A Quick Guide

Brian Gregory

By Brian Gregory
Updated March 24, 2025

Is your air conditioner not cooling properly? Learn how to remedy common AC issues with tips from Lowes.

A central air conditioning unit outside of a brick home.

Check Your Thermostat Settings

A Honeywell programmable thermostat on a wall outside of a living room.

The first thing you should do when trying to fix home air conditioners is to check the thermostat settings. For many units, you’ll have to toggle the HEAT/COOL switch when the weather outside begins to warm up. If you have a digital thermostat and changing the settings to COOL doesn’t help, turn your thermostat completely off, wait a few seconds and restart it before trying anything else.

Check for a Tripped Circuit Breaker

Just as with any other electrical equipment, sometimes your HVAC system can trip a circuit breaker. To find out if yours has, check your breaker box to see if the corresponding switch is in the OFF position. If it is, try flipping it to the ON position. For details, see our related article How to Reset a Circuit Breaker.

Caution

If your HVAC system causes the circuit breaker to trip again shortly after resetting it, don’t reset the breaker again. Contact a professional for an inspection.

Check the Air Filter

A man in a red knit shirt changing an air filter.

A clogged air filter can cause major AC problems, such as poor airflow through vents, inadequate cooling, water leaks from your unit and frozen evaporator coils. Inspect your air filter regularly according to the manufacturer’s recommendations to ensure optimal air flow. For additional help, see Change Your Home Air Filters for Better Air Quality and our Air Filters Buying Guide to learn the correct type of filter for your HVAC system.

Inspect Your HVAC Unit

Excess dirt and debris on the condenser coils of your HVAC outdoor unit can prevent it from operating with maximum efficiency. It’s a good idea to regularly go outside and inspect your HVAC coils and, if you’re comfortable, clean them as needed. Our article How to Clean an Air Conditioner will provide detailed instructions.

Inspect the Air Vents

Although closing off the air vents in your home may sound like a good way to save money on your energy bill, it actually isn’t. Blocked air vents can cause your AC to work harder than necessary and even damage the compressor in extreme temperatures. Each time you perform a routine inspection of your HVAC system, check all the air vents to make sure they’re open. Once you’ve done so, if you don’t feel air coming out of one or more vents, contact a professional.

Get Expert Air Conditioner Repair Services with Lowe’s

Can’t get your air conditioner to work? Lowe’s can help. Request a consultation from our professional HVAC installation and repair services today.

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