A traditional heat pump next to a house showing comparison to geothermal heat pump.

Why is My Air Conditioner Making Clicking Noises?

With any forced air heating or cooling system, there’s going to be sounds associated with air flowing through the duct work, in fact, it’s one of the main reasons people opt for the quieter radiant heat in the winter. Some units give off a light whirl that is ignored as background noise after a homeowner becomes familiar with it, while others sound like an Airbus A350 preparing to leave the runway.

While the sound of airflow is a necessary evil with a forced air-conditioner, there are some other sounds that are an indicator that something may be malfunctioning within the system. One such racket is a persistent clicking noise that may develop within the air-conditioner over time. While the clicking noise isn’t as sinister as a loud banging or the crackling of fire coming from your utility room, it’s still important to be checked out for one of these main causes:

First, Where the Clicking Originates

An air-conditioner can really become the ‘one-man band’ of your home with all the different noises it can emit. Some examples include:air conditioning unit

  • Hissing sounds from duct leaks
  • Buzzing sounds from electrical components (like a relay switch)
  • Bubbling from a refrigerant leak
  • Loud banging from a pump

Luckily the clicking sound is somewhat easy to diagnose because 9 times out of 10 it comes from either the outside compressor/condenser or the inside air handler. The clicking noises fall anywhere on the spectrum from slow at startup to rapid and never ending even after the A/C is supposed to shut down. Luckily, the frequency of these sounds also helps in troubleshooting. Let your HVAC technician know when and how frequent the clicking noise goes on.

Fan Obstruction

The first and simplest area to check is the fan unit on the inside air handler. A clicking noise that starts off slow and progresses as the unit warms up could be coming from an obstruction to the fan or a bent fan blade. Just like putting a stick in a window fan, the click will occur every time the blades hit that obstruction until either the obstruction or the blade breaks away.

Capacitor / Control Board Issues

What many homeowners aren’t aware of is that their air-conditioner does make an audible click every time it starts up. Usually, it’s just one click as the communication between the thermostat sends a signal to the capacitors to fire up.

If there is a constant clicking but the unit won’t turn on, it is an electrical problem. The thermostat is sending the signal but it can’t be put into action because the wires are shorted together, or the capacitor or control board switch (relay) has gone bad. Either way, it’s best to call a service technician.

Compressor Hardware Problems

If the clicking noise is coming from outside the home, it could be caused by an issue with the compressor. It’s not something that should instantly cause alarm, though, as the problem could be nothing more than a bolt that has come loose, or one that wasn’t removed in the first place, such as with shipping hardware. Loose refrigerant tubing could also cause a soft click as the vibration of the unit running causes it to hit the A/C frame.

One thing to remember is that although clicking sounds can range from minor nuisances to aggravating intrusions, it’s always best to call a professional technician to investigate the issues. DIY work on an A/C unit carries the risk of both electrical shock and excessive damage to components so it’s best to leave the job to a licensed A/C expert.

If you’re in the Reading, PA area and are hearing unusual clicking noises in your air conditioner, give us a call today for a further diagnosis on the A/C clicking that has got your heart ticking, or fill out our online contact form.

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