Thermostat clicks but ac does not turn on

Thermostat clicks but ac does not turn on. There are clogged filters in the thermostat that cause the thermostat to click, but even clicking doesn’t turn the AC on.

The AC and the thermostat may not be able to communicate, and thus, the thermostat is only able to make the clicking sound but not turn the AC on.

My thermostat was not working, rather, the thermostat was working, but the AC was not working.

There was a clicking sound in my thermostats that indicated that the thermostat was turning the AC on, but the AC still wouldn’t turn on.

I thought the AC was not working because it had been there for a long time. I wanted to buy a new AC and connect it with my thermostat, but my friend fixed the clicking issue and turned my AC on without a problem. I learned from him.

Thermostat clicks but ac does not turn on

Having a thermostat that turns your AC on in the hot summer is pretty great, but sometimes the AC doesn’t turn on even when the thermostat clicks. The thermostat clicking and the AC not turning on even with the clicking is a bad problem.

The thermostat clicks and doesn’t turn on because the air filter is clogged. The settings of the thermostat may be wrong for the AC.

The communication between the thermostat and the AC may be wrong. The power of the thermostat may be on, but the AC’s power may not be on. Read more below!

AC’s power

ac's power

The thermostat clicking means that the thermostat has power and the thermostat is on, but that doesn’t mean that AC has power as well.

The AC may not have any power from the board, or the AC may not even be plugged in.

The breaker to the AC may be different, and it may be turned off. The power, except the thermostat, may be off. That’s why the thermostat is able to click.

Check the AC and see if the power of the AC is on. The power of the AC should be displayed on the AC’s panel.

Turn the power from the remote on first. If the remote was not used to turn the AC off, then check the plug of the AC. Plug the AC and see if the outlet is on.

Turn the AC outlet on and see the breaker connected to the AC. Turn the breaker of the AC on and make sure the AC receives the power.

Try using the thermostat and turning the AC on after all the connections, and powering the AC. The AC will work after the power of the AC is good. Move to next.

Clogged air filters

clogged air filters

Even more than power issues, the AC not turning on with the clicking of the thermostat actually links to the air filters. The issue of air filters is not a bug issue, but the issue is very annoying.

No professional assistance for clogged air filters is needed at all. The troubleshooting of any AC should begin with air filters. Air filters should be checked and made sure that they are left with clogs.

Accumulated debris and particles enter the air filter, and even the dirt gathers in the air filter, and the air filters of the AC get clogged. The clogged air filter is actually just disrupting the HVAC’s airflow completely.

The thermostat will click when the airflow is disrupted. The build-up of the clog can increase over time, and not just disrupt the airflow, but not turn the AC on at all.

The cleaning of air filters should be done if there is clogging material in them. The filters should be replaced after two or three months.

The filters should be of good quality. Durable filters are pretty great against clogging, though they are not immune to clogging either. Changing the air filter in clogging is a fix too.



If the AC has power and the air filters are perfectly clean, then check the setting of the thermostat.

The setting of the thermostat is an easy trick to solve the AC not turning on and the clicking of the thermostat.

If no air comes out of the vents, then check the setting of the thermostat. The setting of the thermostats is very important, but it might not have the right adjustment.

The temperature of the thermostats should be at a certain level to start the AC. The temperature should be low, and it should be set enough to trigger the thermostat to start.

Check if the temperature of the thermostat is set low or not. It might be that the set temperature of the thermostat is too high, so the triggering of the AC is difficult for it and not turning the AC on.

The temperature won’t start the AC until the low temperature is met to match the triggering. If the temperature of the AC is set incorrectly, then adjust the temperature to low and match the triggering.

Make the adjustment of the thermostat according to room temperature. The setting should be set differently from the room and nearby temperature, or else the triggering of the AC won’t happen.

Faulty capacitor

faulty capacitor

The thermostat may be well in the air filters, and the setting from the thermostat may be correct. Still, the capacitor of the thermostat is another problem that causes the clicking and not letting the thermostat power on.

The capacitor of the thermostat stores the charge and transfers it when the triggering for the AC is required. The capacitor in the thermostat acts like a battery and power the thermostats and even the AC when turned on.

If the capacitor of the thermostat is faulty, you will hear a buzzing sound at the string of the thermostat, proving that the thermostat’s capacitor is faulty.

If the buzzing is being heard from the compressor, You can get shocked by the capacitor as it has a charge, so don’t touch the capacitor.

Get a professional to change the capacitor of your thermostat so that it will be back to normal.

Faulty thermostat

faulty thermostat

If you have set the thermostat to match the triggering temperature, but still the AC is not turning on, then you have a thermostat issue at your hand.

If the thermostat can’t even trigger the AC at the right temperature, then that means that the thermostat is faulty.

The thermostat sometimes has firmware faults, and even physical faults in the thermostat are very common. The thermostat can malfunction. A broken relay system may also be a part of the faulty thermostat.

If you have a relay system that has a fault, then you have to get some fixes ready. The relays are responsible for contacting the furnace and the HVAC system.

The flow of air and the heat turning is present on the thermostat relay as well. If you have a relay as the suspect, check it. Tighten the connections of the loose relay.

Check for the signs that indicate the thermostat is damaged. Try restarting the thermostat. If the thermostat doesn’t power on properly, then the thermostat has many faults. If the thermostat is malfunctioning, get it fixed.


If your thermostat is clicking, but your AC still doesn’t turn on, the setting of the thermostat temperature should be your start. Fix the thermostat’s temperature and check the thermostat’s filter.

Check the capacitor and the power of the AC. Fix the AC and thermostat. Thanks for reading!

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