Why is my A/C overheating?

Did your AC stop working?

If so, one of the parts in your AC could be overheating. When they overheat, the most important parts of your AC will shut themselves down to prevent damage, which means your AC will temporarily stop working.

In some cases, the overheated part may have failed completely, which means it will need to be repaired or replaced.

Below are 3 major AC components that are prone to overheat:

  1. The compressor
  2. Fan motors
  3. Capacitors

In this article, we’ll go into more detail about what causes each of these components to overheat and some fixes you can try yourself.

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Overheating AC compressor

The compressor is the heart of your air conditioning system. Its job is to circulate refrigerant, the liquid/gas substance that’s responsible for cooling your home’s air.

If the compressor begins to overheat, it will shut down to protect itself from further damage. When your compressor shuts down, your AC will stop working.

Overheating puts extra strain on the compressor, which could eventually cause it to break down. Unfortunately, if your compressor is completely worn out, you could face a very expensive repair.

Let’s look at what causes an AC compressor to overheat in the first place.

Causes of an overheating AC compressor

The following issues can cause your AC compressor to overheat:

  • Blocked (or dirty) condenser coils: The coils on the condenser (outdoor unit) help dissipate the heat absorbed by refrigerant. If the coils are blocked by plants or covered in a thick layer of dirt, the refrigerant will struggle to release the heat, which will overwork your compressor.
  • Pressure issues: Your compressor needs a balanced pressure level to operate correctly. If pressure is too low or too high, it can cause your compressor to overheat and overwork itself. The most common pressure issue is having low refrigerant levels, which is usually due to a refrigerant leak somewhere in your system.
  • Worn compressor motor: Over time, mechanical parts can break down due to normal wear and tear. It’s common for your compressor to overheat if you have an older AC system and it’s an especially hot day.

Overheating AC fan motors

Your air conditioner has 2 main fan motors:

  1. The blower motor (located in the indoor unit)
  2. The condenser fan motor (located in the outdoor unit)

If either of the motors become overheated, they will shut down and your AC will stop working.

Causes of an overheating fan motor

Your AC fan motors can overheat because of…

  • Dirty fan blades: If dirt or debris cover the condenser fan blades or the squirrel cage of the blower, it puts extra strain on the motor. This extra strain will cause the motor to overheat.
  • A frozen evaporator coil: The evaporator coil is located in the indoor unit. This is the part that actually cools your home’s air. If your evaporator coil freezes, it could make your blower motor run longer trying to cool your home. Longer motor run times can lead to overheating issues.
  • General wear and tear: Parts inside a motor can wear out over time, causing the motor to overheat as it attempts to keep up with the cooling demand.

Overheating AC capacitor

A capacitor is a small cylinder that stores energy. Its purpose is to help start motors, like the motor inside the compressor or the blower motor.

A capacitor can only run for a short amount of time or else it will overheat and burn out. If the capacitor overheats, the motor won’t start and your AC can’t cool your home.

Causes of an overheating capacitor

The following issues can cause a capacitor to overheat:

  • Power surges: Lightning strikes, damaged power lines and short circuits can all cause a capacitor to overheat and fail.
  • Malfunctioning relay switch: Relays are used to switch your AC system’s high-voltage parts on and off. If a capacitor’s relay switch is malfunctioning, it can let in too much electricity, which will cause the capacitor to overheat and burn out.
  • Old age: Most capacitors last around 6 years. If yours is old, it’s more prone to overheat and wear itself out.

How to fix an overheating AC

Now that you know what causes these components to overheat, let’s look at some ways you can attempt to fix the problem.

Follow these step-by-step instructions:

  1. Check your air filter: If it is dirty, replace the filter and see if that stops your AC from overheating.
  2. Make sure nothing is blocking the condenser coils: If shrubbery or any other objects are too close to your outdoor unit, remove them. Make sure nothing is within 3 feet of your outdoor unit so it can have enough room to release heat.
  3. Call a professional: If the problem persists after you try steps 1 and 2, contact a professional. The rest of the issues we mentioned should only be handled by a certified technician. Any attempts to further troubleshoot the problem on your own could lead to even more damage to your AC system.

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