What are the telltale AC compressor overheating symptoms?

Understanding AC compressor overheating symptoms can help you take prompt action and prevent further damage to the compressor.

That being so, today, we’ll explore the common indicators of an AC compressor heating up.

Additionally, we’ll look at the possible causes behind this issue and also provide you with the solutions to fix it.

AC compressor overheating symptoms

1.      The AC is frequently cycling on and off

Here’s the thing: ACs normally have a compressor thermal switch that trips when the compressor overheats.

Pro tip: The main purpose of this switch is to prevent compressor damage due to overheating.

Now, when the compressor overheats, your AC will cycle off till the compressor cools before it cycles on again.

And, the process will repeat itself (without your room ever reaching the set temperature).

2.      Reduced cooling capacity

As we have just seen, an overheating aircon compressor will result in frequent cycling of the unit.

In turn, this will lead to inconsistent cooling as the AC struggles to reach the set temperature hence reduced cooling.

As you might have already figured out, your house will inevitably be warmer than you desire.

3.      Elevated indoor humidity levels

As we have just seen above, an overheating AC will not cool the room properly.

As a result, it will also not be in a position to reduce the humidity levels.

4.      Warm air blowing from the vents

When your AC compressor is heating up, it will struggle to compress and pump the refrigerant properly.

As a result, if you put your hand close to the vents, you might note that they are blowing warm air even if you’ve set the AC to cooling mode.

However, this is not a clear sign that the compressor is to blame.

At times, it could also be due to the refrigerant leaking.

But, even if it’s the refrigerant that is leaking, it will also result in the compressor overheating.

This is because the compressor will try to cool the room using the little remaining refrigerant.

5.      Your AC is producing unusual (and loud) noises

Now, the most common noise that might be made by an overheating aircon compressor is a buzzing noise.

Typically, this noise indicates that there might be an electrical issue with the compressor.

And, it could be that this issue that is resulting in your AC compressor heating up.

Another common noise you might hear is a grinding noise – indicates that the compressor is hard starting (we shall talk more about this in a few).

6.      Circuit breaker tripping frequently

When the compressor overheats, it might start drawing too much power from the outlet leading to the circuit breaker tripping.

Pro tip: Remember that the circuit breaker acts as a safety mechanism to avoid fires. As such, do not just keep on resetting it. Instead, have a HVAC technician to come and inspect your aircon.

7.      The AC vibrates a lot

Though not common, at times you might note that your AC is vibrating more so when it is starting – hard starting.

For the most part, this points to a faulty (or misalignment) of one or more internal parts in the compressor.

As a result, the AC will vibrate a lot indicating that it is struggling to start and stay on.

In most cases, this will occur when the compressor is almost fully gone and needs to be replaced.

AC compressor overheating symptoms – what causes AC compressor overheating

For the most part, overworking the compressor is the chief cause of it overheating.

With that in mind, below are the most common causes for your AC compressor overheating:

  • Dirty filters
  • Dirty/frozen coils
  • Faulty condenser fan assembly
  • Using the AC in an oversized room
  • Improper installation of the AC
  • Leaking refrigerant
  • The compressor is old and its parts have worn out

Now, for a deeper look into how these factors cause your AC’s compressor to overheat, read our other article: Why is my ac compressor overheating and shutting off?

AC compressor overheating – solutions you can try

1.      Clean the filters and coils

Normally, dirty filters and coils will exert more pressure on the compressor as it tries to cool the house.

In turn, this might cause it to overheat.

With that in mind, be sure to frequently clean the filters (if possible, every two weeks) and condenser coils when need be.

As for the evaporator coils, if you note that ice is building up on them, temporarily shut off the unit for the ice to thaw.

2.      Follow the AC installation guidelines

For starters, make sure that you aren’t exposing your AC to direct sunlight as this will impede its cooling ability.

Also, make sure that there is an open spacing of at least 15cm surrounding the tops and sides of the AC – remove any curtains or furniture that might impede airflow.

And, if you have a split AC, have it mounted at a height of 7 to 8 feet from the ground.

Something else: Make sure that the doors and windows are closed to avoid outside heat finding its way into the room.

3.      The room might be oversized

This is especially so if the AC is new or has been installed recently.

You see, there is a possibility that you’ve placed an AC designed for a smaller room into a bigger room.

This will result in the AC working harder than it should and thereby overheat the compressor.

With that in mind, be sure that your AC is powerful enough to cool your room depending on the room’s size.

If it isn’t, you should consider getting a new AC with higher BTUs.

4.      Check the condenser fan assembly

Here, you will be confirming that the fan motor is running.

Now, if the fan motor isn’t running, you ought to replace it – check current condenser fan blade prices on Amazon.

Also, make sure that the fan blade is not broken.

Again, if it is, get a replacement fan blade

5.      Check the refrigerant level

Earlier on, I mentioned that a low refrigerant might cause the compressor to overwork.

That being so, you can look to see if there is a refrigerant leak somewhere along the AC.

Unfortunately, only an EPA-licensed HVAC technician can handle (and recharge) the refrigerant as it is toxic.

6.      The compressor is old – wear and tear of compressor parts

With age, it is inevitable for the compressor parts not to wear out.

Now, if you have been using the aircon for more than 15 years, there is a high likelihood of the parts starting to wear out.

Subsequently, they won’t be able to perform their job for long without overheating.

Pro tip: For the most part, this is normally accompanied by the AC hard starting (vibrating) as it starts.

At this point, it’s best to just get a new AC.

However, you can have an EPA-licensed HVAC technician overhaul the AC compressor or swipe it out with a new compressor. But, beware that it might not last for long.

AC compressor overheating symptoms – Frequently Asked Questions (FAQ)

Why is my AC compressor overheating and shutting off?

This might be as a result of one of the following reasons:

  • The room might be oversized for the AC.
  • Dirty condenser coils or filters.
  • Frozen evaporator coils.
  • The refrigerant is leaking.
  • The AC might be in direct sunlight or there are curtains/furniture obstructing it.
  • AC might be old and the compressor parts are wearing out.

AC compressor overheating symptoms – parting words

When it comes to the performance of your aircon, recognizing the signs of an overheating AC compressor is essential.

The above symptoms can be early warning signs that something is not right with your aircon.

Bearing that in mind, it’s advisable that you diagnose and address the issue promptly to avoid further damage to the unit.


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