Why Your Thermostat Keeps Clicking On & Off – Common Causes & Easy Fixes

Has your thermostat been making clicking noises, and you don’t know whether it’s normal or something to be concerned about? Well, in most cases, if the noise only appears when you’re turning your thermostat on and off, the clicking noise is absolutely normal.

However, if the noise seems unusual to you, or you used to hear a clicking sound but it’s not there anymore, chances are something is wrong with your HVAC system. What could be the cause, and how do you fix it? That’s what we’ll be talking about here.

What Causes an Unusual Clicking Sound

There are a few reasons why your thermostat might be making weird noises, including:

• Improper installation and aging equipment – Have you had your thermostat replaced recently? Or maybe you took it off your wall to do some light repairs? Whatever the reason was, if you did take it off, then it’s very probable that the cause of the noise is simply improperly installed thermostat – especially if the thermostat seems unusually loud. Another reason for your thermostat making a clicking noise when it shouldn’t is its age.
• Low batteries – Sometimes, the clicking noise is your thermostat’s way of informing you that its batteries are on low levels and that you’ll need to change them soon.
• Dirty or faulty contacts – Another very common reason why you could repeatedly be hearing clicking noises is dirt – your thermostat, just like any other item in your house, will accumulate some dirt. If it’s not cleaned frequently enough, it can result in communication problems with the HVAC due to dirty contacts.
• Temperature fluctuations – If you subject your thermostat to frequent temperature changes, it might end up clicking more often, simply because of more frequent use. It can, however, also hint at a need for recalibration.

Troubleshooting Your AC Clicking On & Off

Troubleshooting most of these issues is rather easy and depends on what exactly is the issue.

Improper Installation or Aging Equipment

If the issue is caused by improper installation, then we would definitely recommend leaving fixing it to a professional – especially considering that if you install it improperly again, you are exposing your HVAC unit to potential further damage, as well as yourself to a safety hazard. Seasoned professionals will be able to re-install your AC unit thermostat properly, and make sure that it is suitable for your home in terms of size.

If your thermostat is quite old (typically that means around 10 years, although each situation is different), then it might be time to replace it rather than have someone come and repair it again and again.

Low Batteries

This is probably the easiest thing to fix when it comes to a thermostat making clicking noises – all you have to do is change the batteries, and you’ll be good to go. The only issue you might encounter here is not knowing what batteries to buy, but that can be easily fixed with the help of a sales representative or a simple internet search. If you still can’t find it, there is almost always a manufacturer line that you can call and ask.

Dirty or Faulty Contacts

If your thermostat’s contacts are dirty or faulty, you can clean them by following this instruction:

1. Turn the power off – never clean the contacts when the HVAC system is on. If your thermostat uses batteries, remove them as well.
2. Remove the thermostat’s cover.
3. If you have a mechanical thermostat, turn the settings up until the contact points close, and use a clean paintbrush or compressed air to clean the debris. If you have a smart thermostat, on the other hand, you can use a q-tip with rubbing alcohol to clean it.
4. Mechanical thermostats will also require you to clean the bimetal coil and switch contacts. For the latter, you can use a q-tip dipped in rubbing alcohol, while for the former, you can slide a dollar bill between the coils – it will collect the debris that might be stuck there.
5. Once everything is dried and clean, you can reassemble your thermostat and, if needed, replace the batteries.

It’s important to mention that if you see any wires or elements that look corroded, do not attempt to fix them yourself – instead, leave it to a professional that knows exactly how to change them without putting others, or themselves, at risk.

Temperature Fluctuations

If the fluctuations are caused by you changing the temperature often, then the solution would be to stop or minimize how often you do it. However, if the thermostat does it by itself, then you might have to recalibrate it – a step by step guide should be included in the manual, and if you don’t have it, you can always find it online.

Sometimes, temperature fluctuations are caused by factors outside of yourself or the thermostat. For example, if your home has poor insulation and you have a smart thermostat that adjusts the temperature based on your indoor temperature, then poor insulation that lets cold in can cause several fluctuations.

When to Call a Professional

When it comes to the thermostat clicking on and off, most times, a homeowner can fix it.

However, it’s important to know your limits. If you don’t feel comfortable doing something involving your HVAC system yourself, it’s always better to call a professional. Doing something without knowing how to can result in putting yourself and others at risk, so it’s safe to say that it’s not worth it.

The Bottom Line

A thermostat clicking on and off is usually nothing to worry about – it’s a completely normal sound that lets you know your thermostat is working properly and changing temperatures. In fact, you should be more worried if it doesn’t click, as it might indicate a malfunction or an issue with the power supply, among other things.

However, if the clicking sound has started to sound differently than it used to (for example it’s louder), then it might be a good idea to either check for a malfunction by yourself, or ask a professional to do it, especially if you don’t have experience with air conditioning and heating systems.

At Meadow Air, we understand the importance of having a reliable air conditioning and heating team in your corner so that whenever an issue arises, you know you can count on them to come to the rescue – and that’s precisely what we do. We have been providing Arizonans with reliable HVAC services for years now. So, next time you have trouble with your HVAC thermostat, and you’re located within the Phoenix area, don’t hesitate to give us a call.