Help! My AC Clicks But Won’t Come On. A Florida Tech Explains Why

August 17, 2021

When you turn on your air conditioner, you expect to feel cool air, not hear an annoying clicking sound. If your AC clicks but won’t come on, it’s time for some troubleshooting. Before you can determine the cause of the AC malfunction, first pay attention to where the clicking is coming from.

In this article, we’ll go over checking three areas that could be the source of the clicking:

  • Thermostat
  • Indoor unit
  • Outdoor unit

You will need a professional to fix a clicking issue. But, read on for the information you need to determine the possible problem before you call in a professional HVAC technician.


Need a Florida tech ASAP for your AC repair? Contact Advanced Air to get to the source of the clicking (day or night with our 24/7 Rapid Response Line)!


Check Your Thermostat

Advanced Air technician checking a thermostat.

The thermostat is an integral part of your AC system and is responsible for starting or stopping the cooling process, depending on your input setting. When you adjust your settings, you may hear a quick, soft clicking. This is usually due to your AC’s relay turning your AC on and off.

If that clicking is loud and/or continues for more than a few seconds, you probably have an issue with a broken relay or a worn wire in your thermostat. Contact a professional technician to identify and fix the problem.

The bottom line: If the thermostat is the culprit, you will hear a loud clicking when you’re near your thermostat.

Check Your Indoor Unit

If you hear clicking coming from somewhere in your house that isn’t the thermostat, your indoor unit is to blame—specifically, your AC’s control board.

You can think of the control board as the middleman since the thermostat’s wires feed into it. The control board functions by receiving signals from your thermostat then sending them to other parts of your AC to cool your home or stop the cooling.

If your control board is malfunctioning due to an electrical issue, it won’t pass the message to other AC parts. Instead, it’ll receive the message, timeout, and fail. A glitching control board requires a professional to assess what’s causing the problem and repair it.

The bottom line: If the control board is the culprit, you will hear clicking coming from your indoor AC unit.

Check Your Outdoor Unit

Outdoor A/C.

Don’t hear clicking coming from your thermostat or indoor unit? It’s time to take a stroll outside. If the clicking is coming from your outdoor AC unit, the problem is most likely a failed contactor or capacitor.

A failing contactor

Your AC’s contactor is basically a big switch that turns your compressor and condenser fan on and off whenever it gets the signal from your thermostat.

If your contactor is malfunctioning, damaged, or old, your AC won’t start. Instead, you’ll hear a clicking sound, which indicates that a professional AC technician needs to replace or repair the contactor. Do not try to replace this piece yourself; your contactor stores a high voltage and can severely shock you or damage your air conditioning system.

The bottom line: If the contactor is the culprit, you will hear clicking coming from the outdoor unit but no humming or buzzing.

A failing capacitor

Your AC’s capacitor is a large battery that stores an electrical charge and releases the energy your compressor needs to start running. Without a working capacitor, your AC cannot start its fan motors and cool your home.

With a worn or damaged capacitor, the AC’s motors won’t have enough energy to run consistently. If the motors run without that initial surge of electricity, they could be damaged, causing an extensive and expensive AC repair.

Don’t try to fix a malfunctioning capacitor yourself for similar reasons to the faulty contactor. Contact a professional AC technician.

The bottom line: If the capacitor is the culprit, you will hear a clicking noise coming from your outdoor unit, followed by a soft hum or buzzing noise.

Contact the #1 source for fixing AC clicking: Advanced Air

Advanced Air technician inspecting AC.

When it comes to AC repair, look no further than Advanced Air. Whatever the cause of your clicking AC, our professional technicians will identify the bad part and replace it.

Just read any of our 5-star reviews to see why homeowners in Southwest Florida trust us to get the job done.


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