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How to tell if home AC compressor is bad?

Has it ever happened that you notice, on a hot summer day, your home air conditioner is not cooling the rooms as before?

It often puts us in a dilemma whether to call in professional help or find our own way around the problem when our home air conditioner starts performing abnormally.

When such a thing hits us on a hot day, we often wonder – How to tell if the home AC compressor has gone bad!

To recognize this, we need to understand the working of an air conditioner and its components. An air conditioner has a compressor, condenser coil, expansion valve, evaporator coil, and a refrigerant.

When one of these components goes out of rhythm, the overall working of an AC gets affected. Most of the times, it is the compressor that is damaged due to some reason. Today, we shall look at the ways to identify a faulty AC compressor. But before that, here is how the AC works.

General working of an Air Conditioning unit

A refrigerant is a cooling element in an AC. A compressor compresses the refrigerant to high pressure and conveys it to the condenser coil.

The condenser is a copper coil that facilitates heat transfer. The condenser coil is located in the external unit of an AC that spews hot air out of our homes.

A fan blows over the condenser coil and cools the refrigerant flowing from the compressor. This removes the heat from the gaseous refrigerant turning it into liquid. The liquid flows to an expansion valve. The expansion valve is a thermostatic valve- a metering device that depressurizes the liquid.

From the expansion valve, the refrigerant is pushed to an evaporator coil. The evaporator coil is the component that draws heat from your home and cools the indoors.

A fan blows air on the evaporator coil removing ambient heat from the air, and making it ‘cool’, which later flows into your home. The refrigerant flows back to the compressor and the cycle is repeated over and over again to achieve indoor cooling.

This is called the refrigeration cycle.

Symptoms that your home AC compressor is not working properly

We won’t bore you with any more technical details. Instead, we will show you the ‘symptoms’ of a defective AC compressor’s performance. Let us go one by one.

  • The cooling power is lower than usual

The early and the most obvious signs of AC compressor damage is when we notice that it takes more time to cool the same space than before. When the AC compressor is bad, less cold air is generated and therefore the cooling of a room decreases.

Another sign is – you can hear the compressor running but there is no/ less airflow. However, before you arrive at the conclusion that your AC compressor has gone bad, check the vents/ducts too – dirty clogs can also cause less airflow.

  • Rattling noise

There can be a number of reasons for rattling noises in an AC. However, the types of noises can also indicate different types of problems.

A ticking sound similar to that of a gas burner, when turned on, is due to the wearing out of the electrical relay. The ticking sounds are usually small sparks, and require the attention of an HVAC expert.

If you experience a clicking or rumbling noise when the AC is switched on, it is an indication that the compressor mounting may be loosened due to constant vibrations. Call in your HVAC expert immediately to fix the loosened mounts.

  • Tripping of circuit breakers

Does the circuit breaker in your house keep tripping when you switch on the AC.? This is because the AC compressor may be overheating or drawing in more electricity. This can cause the circuit breaker to trip and you can identify it by the outside condensing unit losing power at different times.

Resetting the circuit breaker repeatedly and turning the AC on is not going to help it; the AC compressor needs immediate attention and technical expertise. In such a scenario, call an HVAC expert quickly.

  • Puddles and leaks

If you see puddles of water or moisture anywhere around your home AC, it is a sign of refrigerant leakage. On the flip side, if you experience constant headaches, irritated eyes, coughing, nausea, etc. then it is due to the refrigerant leaking into the house.

Refrigerants are health hazards and therefore they come hermetically sealed in the AC compressor. A hermetic seal means no air or fluid can enter or leave a container. AC compressors are hermetically sealed to keep the chemical refrigerant inside the system at all times.

There is no guesswork here – immediately summon your HVAC technician after switching off your home AC. Refrigerants are expensive to fill, and therefore there might be unexpected expenses that you may need to accommodate in such a scenario.

How to tackle a faulty AC compressor?

The first thing is to identify whether the compressor has really gone bad; this is often reflected in poor indoor cooling temperatures or by noises. Another sign is that your electric bills are higher than usual, especially during summer.

Lastly, if the AC shuts off before the house cools; it may be due to ‘short cycling’. Short cycling means the AC shuts off without completing the cooling cycle before the desired temperature is reached.

Short cycling is not necessarily due to a faulty AC compressor. This could be due to problems with the thermostat, dirty air filters or due to insufficient tonnage of the AC with respect to the space/ size of the room. However, cleaning them can get you rid of short cycling.

So, when it is time to take action, look for signs mentioned above in the post and try to locate the problem or at least have a fair understanding of the working of the AC and its problem.

SWITCH THE AC OFF – wait no further. Call an HVAC expert/ technician immediately and attend to the problem.

Technical aspects of our day-to-day use appliances can be daunting, especially when they have problems. If you have any questions or doubts related to this topic, then comment below now. We would be happy to address them and close your queries.