3 Common Reasons a Home A/C Will Overheat and Shut Down

Imagine you get home from a hard day of work, only to realize…your air conditioner isn’t working. Your home is hot and muggy, and you’re a sweaty mess already!

This is a common scenario when summer hits and the air conditioner overheats. When it overheats, it will trip the circuit breaker—and continue to do so until you fix the problem.

Here are 3 common reasons why this happens, and what you can do about them.

1. Dirty air filter

The air filter is the safety net that protects your air conditioner from dirt and pollutants. But when it’s covered in dirt, it goes from friend to foe.

A dirty air filter blocks airflow in your home’s air ducts, forcing your air conditioner to run longer—and harder— to cool your home. This will continue until:

  • The air conditioner breaks down
  • The air conditioner overheats, tripping the circuit breaker

You don’t want either, right?

Solution: Change the air filter once a month. That’s all!

Out of air filters? Here’s our guide to choosing the right air conditioner air filter.

2. Dirty condenser coils

Condenser coils are refrigerant-filled tubes running through your air conditioner’s outside unit. If these coils are dirty, then your air conditioner runs longer, causing the air conditioner to overheat.

Here’s why: Your standard split A/C unit has 2 parts: the outside unit and the inside unit. The inside unit uses refrigerant to absorb the heat in your indoor air to cool it down. That hot liquid refrigerant flows to the outside unit where the refrigerant dumps the heat out into the world.

But if dirt covers the coils, the refrigerant can’t release the heat easily because dirt is an insulator. Basically, it’s like if you were wearing a sweater on a hot day. Your body would want to release the heat, but the wool would prevent the heat from leaving (talk about overheating!). So now the refrigerant can’t absorb more heat from your air, causing your air conditioner to blow out lukewarm air. Or worse.

Your air conditioner will keep running until it overheats because it can’t reach your thermostat temperature setting.

Solution: Clean your outside unit using a special coil cleaning spray. Or call a professional to do it for you as part of a standard air conditioner maintenance visit.

3. Low refrigerant

Similar to problem #2, not having enough refrigerant will also cause your air conditioner to constantly run, leading to it overheat.

Solution: Look out for the signs of low refrigerant:

  • Home isn’t being cooled as quickly as it used to
  • Air conditioner has a hard time cooling your home on very hot days
  • Outside unit is covered in ice

If you’ve noticed these signs, then you’re low on refrigerant. If you’re low on refrigerant then you also have a refrigerant leak because refrigerant is never “used up” like gas in a car.

If you notice any of these signs, contact a professional air conditioner repair person. The professional should:

  1. Confirm there’s a leak
  2. Evacuate what refrigerant there is
  3. Repair the leak
  4. Charge the air conditioner with enough refrigerant

Anyone who tries to add refrigerant without looking for a leak is most likely trying to scam you, because they know you’ll have to call them again when you run out of refrigerant again.

Service Champions, your local heating and air conditioning company, serves San Jose, Sacramento, East Bay and the surrounding areas. For more information on any of our products or services, contact us online.

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