Skip to main content

What's That Clicking Sound From My Air Vents?

Learn more about what that clicking sound might mean and why it can be dangerous.


It’s normal to hear clicking noises coming from your HVAC system when it turns on or off. Your thermostat has to communicate with your heater or AC to trigger heating and cooling, and it may click during this communication process.

But if you hear a clicking that is persistent or continues while either HVAC system is running, something is wrong. It’s easy to ignore clicking because it is not always loud, but you definitely want to pay attention and get expert help if you do hear a persistent clicking sound from air vents. Keep reading to learn more about what that clicking sound might mean and why it can be dangerous. 

Common Reasons for HVAC Clicking

One of the most common clicking noises that we see is a fan obstruction. It’s possible that one of your fan blades is bent just enough that it taps one of the walls as it turns. If this is the case, the clicking noise will start off slow, and then get faster as the fan begins to spin. When the fan is off, you won’t hear the clicking sound. If left alone, the fan blade may continue to bend and the clicking may turn into more of a tapping or banging sound, depending on the severity.

If you hear clicking on your outside unit, it is most likely in the compressor where the air is cooled using refrigerant. There may be a loose part inside of the air compressor knocking around and causing a clicking sound. It’s also possible that clicking can originate from the electrical control, relay, or capacitor. All of these are dangerous if they're allowed to continue without being addressed.

While you don’t ever want to have HVAC problems, when it comes to clicking the best-case scenario is that your thermostat is defective. If this is the case, it’s a simple malfunction that is causing your thermostat to continue trying to communicate with your HVAC system. We can simply recalibrate or replace the thermostat. 

While this isn’t a big problem in and of itself, it can still cause damage to your HVAC system if your thermostat is signaling it to turn on and off frequently, leading to short cycling. If the clicking sound actually originates from within your HVAC system and not the thermostat, it may be a bigger problem. 

Addressing HVAC Clicking

You may be tempted to troubleshoot clicking noises by doing a search online and coming up with your own solution. However, you can do more damage than good if you don’t know what you’re doing. It’s better to call on our expert team of HVAC technicians.

If the problem is with the electrical components, it can even be dangerous to try and fix clicking noises on your own. The best thing you can do is turn your unit off completely so that it does not continue to run in case the clicking noise is causing damage. Leave the system off until our team can determine what the cause is and offer a solution.

Contact Chase Heating and Cooling today to schedule an appointment with our professionals. We're "Keeping Homes Comfortable In All Seasons."