Thermostat Clicks But AC Does Not Turn On

Is It Normal That My Thermostat Is Clicking?

Almost everyone at some point has heard their thermostat making clicking on and off noises as it is coming on or even while running, but are these noises normal, and what do you need to know about them? In this article, you will learn how to diagnose a common air conditioner thermostat issue.

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What Is a Thermostat?

A thermostat is a device connected to the HVAC system that lets you set the desired temperature for your home. It constantly monitors the ambient temperature and turns your heating or air conditioning system on or off to maintain the temperature setting. Programming your thermostat appropriately can help you save money on energy costs.

How Do Thermostats Work?

There are many types of thermostats still in operation, depending on the age of the home or HVAC system. Most modern thermostats are electronic. They work like a small computer, with sensors that monitor the temperature in the home. Most are programmable, and many are wifi enabled, allowing homeowners to monitor and adjust temperatures from anywhere.

However, older homes could still have electromechanical thermostats that work differently. Electromechanical thermostat systems contain a metal strip or bi-metal coil that moves as the temperature changes. When that movement occurs, it tips a small vial containing mercury to one side. As the mercury moves, it signals to the HVAC system that either the heater or air conditioner needs to turn on.

No matter what type of thermostat is in your Phoenix, Arizona home, frequent temperature fluctuations can cause your system to work harder. If you are always adjusting your thermostat to get more comfortable, your system won’t work as efficiently as it should, costing you money. When you can’t get the temperature regulated automatically, you may have a problem and be in need of furnace or AC repair. Give the team at Day & Night a call for a service appointment to see if you may have a problem with your HVAC system or with your thermostat.

person adjusting smart thermostat in home

Why Does My Thermostat Keep Clicking On and Off?

Everyone has heard it at one time or another, whether in your house, a hotel room, or someone else’s home: that telltale click preceding the warming or cooling rush of air from the vents when the system turns on. You might be wondering ‘Why is my thermostat clicking?’ Is the clicking sound normal, or does it signal a problem? If this routinely happens in your home, you can relax. Your thermostat making clicking noises is normal and is what is supposed to happen. It is very common to hear a noise from the thermostat as the HVAC system comes on.

Interestingly, you should be concerned if you do NOT hear the thermostat clicking on and off. That could be telling you that you have a problem with your HVAC system. It is normal for sounds to come from the thermostat as the system starts or stops, so if you don’t hear anything, your system may not be turning on or off. If this happens, give us a call at 602-910-3078.

What Is the Clicking Sound on the Thermostat?

We’ve already answered the question of why do thermostats click on and off and assured you that the sound is normal. But what is the noise? The clicking sound of your thermostat is caused by two small mechanical relays connected inside your HVAC system which move when the internal circuit of the thermostat determines it is time to signal the HVAC to turn on or off.

Every thermostat makes these clicking sounds. However, due to other sounds in the room at the time or how well-insulated your thermostat is, you may not always hear it. Rest assured, if you do, you can breathe easily knowing that it is normal. Think of it as a sign your HVAC system is working as it should.

Programmable Thermostat
Programmable Thermostat

Is There Any Way to Stop Thermostat Clicking?

While most people are happy to know their system is working as it should, some people may be sensitive to sounds. It could also be possible that you have an overly enthusiastic thermostat that sounds louder than necessary. If your thermostat is bothering you when it clicks, there are some options available to remedy the situation.

One way to dampen the sound is to install additional insulation around the thermostat. While it doesn’t change the sound, it can make it harder to hear. Another option is to look at getting a smart thermostat with an integrated circuit. These types of thermostats are silent because they don’t have electromechanical relays.

If your thermostat clicks but AC does not turn on, contact our team at Day & Night Air to discuss options for making it quieter so you can get back to resting undisturbed.

Does a Thermostat Clicking On & Off Ever Mean There’s a Problem With Your HVAC System?

Although a thermostat clicking on and off is typically normal, there are times that it could signal a problem. If your thermostat keeps clicking constantly, your HVAC system could be cycling on and off too frequently. That is definitely something that is not normal and should be checked by our furnace repair team. Give our team a call so one of our certified HVAC technicians can see what is going on.

There are several reasons you may hear more noticeable clicking or no clicking at all. Let’s look at some of the causes.

  • A Loose Mounting - Your thermostat is contained in a housing. If you had to remove that for some reason, whether to paint, replace batteries, or other reasons, you might notice the clicking has gotten louder. It is possible the cover could be slightly out of alignment, not sealing into place correctly. Try adjusting the housing and tightening the screws to see if that corrects the problem.
  • The Setting Is Too Low - If you haven’t heard any clicking, your system may be set too high or low. Your thermostat should be set slightly above the current room temperature for heat and slightly below for cooling. If it isn’t, you may need to adjust it until it comes on, then readjust for comfort after it is on for a bit.
  • The Gas Supply Is Off - If you have a gas furnace, you may hear clicking without any heat coming on. When that occurs, the gas may be turned off, or your pilot light may have gone out. Make sure your gas supply is set in the “on” position and that the pilot light is it. Contact your gas company immediately and leave the home if you smell gas.
  • Your Air Filter Needs Replacing - Your air filter is there to catch contaminants like dirt and dust before they can get to your system. If your filter is clogged, it can’t take in the air that the HVAC system needs to work correctly. If you hear unusual clicking or no clicking at all, make sure your filters aren’t causing problems with your air circulation. Changing your filter at least monthly can keep your system working efficiently.

Have a Professional Take a Look at Your HVAC System

Contact us at Day & Night Air today if your thermostat keeps making clicking noises or your heating or cooling system isn’t working as expected. We can set up an appointment with one of our certified HVAC technicians to quickly assess, diagnose, and repair your issues. If you haven’t already had your annual checkup, now is the time to have your system checked to prevent issues and make minor repairs before they can become big expensive issues.