Air Conditioning Capacitor Making Noise-What to Do

Air conditioning capacitor
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An air conditioner capacitor is a part of that air conditioner responsible for charging and starting the motor. Most of the time, the air conditioners make noises when starting, running, or stopping. Manufacturers have tried to reduce the level of noise produced by the fans. A good fan produces a soft and steady noise.

However, when the ac makes louder noises that have disturbance, especially the rattling noises, there is something wrong with the AC. Most of the time, this noise is always caused by the falling motor or the capacitor. This article discusses some of these noises produced by capacitors and other parts of the air conditioner.

Air conditioning capacitor making noise

ac capacitor making noise

Sometimes you may find that the capacitor of the air conditioner is making some humming noises. When the capacitor fails, it produces a soft, steady, and humming noise and therefore needs some repair.

Most people understand how the failed motor can bring about despair in the air conditioner but do not understand that the air conditioner cannot get the energy to stat without the capacitor. So, in any case, if you hear a humming sound from your air conditioner, it’s good to check the problem or call a technician to fix the problem.

AC noises and what they mean

Air conditioning capacitor making noise

The air conditioner may make many noises, and it’s difficult to notice the exact source of the noise. Due to this, it is good to know what causes them and what can be done to solve the issue. The following are some of the AC noises and what they indicate.

The rattling and banging sounds

If you get a rattling or a banging sound coming from the air conditioner, it shows that the air conditioner compressor or the fan has a broken part. To fix this, inspect the fan from outside and also remove the cover to diagnose any damage which might be available. If there is no obvious reason, estimate on the repair so that you can know whether to do a full replacement or just repair.

If the rattling sound comes from the furnace, then it means the fan motor might be broken.

Loud buzzing noise

Buzzing noise from the air conditioner can be caused by several issues, including the following.

1) A damaged contactor. When the air conditioner contractor is bad, there is power prevention from flowing to the compressor, which will cause the compressor to stop running. A loud buzz is produced instead because the power has flowed to the compressor but not through it.

2) A bad capacitor. A damaged capacitor will prevent the fan from functioning and thereby can cause a buzzing noise.

3) A damaged compressor. If the compressor is obtaining power but not functioning, the air conditioner will produce a buzzing sound.

4) Vibrations. If the air conditioner has loose parts, it will produce vibration noise, sounding like the AC is buzzing.

5) The air conditioner can produce a buzzing sound when it is freezing.

Pulsating noise of the air conditioner

The uninsulated compressor movements can cause pulsating sounds from the air conditioner. If the air conditioner is on a plastic pad, the movement of the compressor is transferred to the plastic, and pulsating sounds are produced. The pulsating sound is more of a metallic whirring; it could be a loose fan or blade wobbling.

Hissing noise

The hissing noise in the air conditioner is mostly caused by refrigerant that is leaking.

Loud squeaking noise

A squeaking sound in the air conditioner is caused when the motor bearings of the AC get damaged.

Whistling noise

A whistle conditioner whistling sound is caused by dirty filters when air travels around the furnace cover. When the air can’t get through the filters, the motor blower forces the air into the system, causing a whistling sound as the air passes through the tiny spaces.

Signs of a bad air conditioning capacitor

Air Conditioning Capacitor

Sometimes the air conditioner may fail to work or may have some complications which need to be fixed. Some of those complications may be caused by a bad capacitor. There are different signs which show that the capacitor is bad or has failed. These symptoms are:

1. The air conditioner will fail to blow cold air

Ac Ac blow cold air

It is the first sign that is easily noticeable by the air conditioner owners.  Since the capacitor is responsible for charging the motor, its failure means that the motor will not start, and thereby, the air conditioner will not blow cold air. Make sure you turn the air conditioner on and off several times to see whether the problem persists. Call for professional help if the problem persists.

2. Humming noise from the capacitor

When you turn your air conditioner and hear a humming noise, it shows that the capacitor may be failing. Again if the noise is produced and the air conditioner is hesitant to start, it indicates that the capacitor may be failing.

3. Increased energy bills

If the energy bills for the air conditioner are rising than usual, it is important to check the condition of your air conditioner capacitor. When the capacitor is in bad condition or is failing, the air conditioner will have to work harder, and therefore more energy is used. The harder the AC system is working, the more energy is used.

4. The air conditioner turns off and on-its own

Sometimes the air conditioner may turn on and off frequently on its own. The act shows that there might be something wrong with the power generation in the air conditioner. Therefore it is important to check on the capacitor condition because it might be failing.

5. The HVAC system is old

When the HVAC is getting old, it comes to some point that it stops working due to one reason. The system might be too old, and it goes through problems of refusing to work. The only thing that you will need to do to your HVAC is to replace the capacitor with a new one.

6. When the air conditioner does not turn on immediately

The air conditioner may take some time to start after turning it on. That is a sign of a failing capacitor that needs to be fixed.

7. The air conditioner fails to turn on

Since the air conditioning capacitor is responsible for charging and starting the motor, it means that in any case that the capacitor fails, the motor will not have any charge and will not start. Therefore, the air conditioner will also not turn on and function.

Causes of a noisy air conditioning unit

  • Slipped belt. A slipped belt in the air conditioner makes a squealing noise.
  • Loose parts of the air conditioner. If the screws or any other part of the air conditioner is loose, you will hear a rattling noise since the looser the part, the more the noise.
  • Dirty fan.
  • Air conditioner capacitor failure or the failure of the fan motor.
  • Ducts leakages
  • Malfunctions of the electrical.
  • Compressor failure.

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In conclusion, a capacitor in the air conditioning system works like a battery that will help in the start-up of your AC. After a long time using the capacitor, some complications can occur and cause, and the capacitor starts producing some buzzing noises. The buzzing noises are heard from the outdoor unit.

Again, the AC capacitor may produce some clicking sounds during the start-up. It is advisable to see a professional technician to fix the problem if any of these noises in the capacitor occur. Again, if the AC capacitor is not producing charge, it means that it has failed and therefore needs to be replaced.

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