Why Your Nest Thermostat Keeps Turning The AC ON/OFF 2022

Why Your Nest Thermostat Keeps Turning The AC ON/OFF 2022

Do you know why your nest thermostat keeps turning the ac on/off? If not, don’t worry, this guide will help you with it. Have you ever experienced an appliance that keeps turning the air conditioner on or off, when you don’t touch it? This is what happens with most of our thermostats. 

You think the system is working correctly and you leave the house, only to come back and find the system still in the “off” mode. But why is this happening? Let’s take a look at how your Nest thermostat works and why it might keep turning the air conditioner on and off.

Why Does The Nest Thermostat Keep Turning The Air Conditioning On And Off?

Nest Thermostat Keeps Turning The AC ON/OFF

The thermostat may have a faulty or missing C wire, the batteries may be low, or it could be a reset problem, as the Nest thermostat keeps turning the AC on and off.

The temperature in my house was way too cold, but I wasn’t sure why since we didn’t have any fans on. I figured it must have been a faulty temperature sensor since the unit still functioned in the other rooms.

Faulty Or Missing C Wire

The C wire in your thermostat may be malfunctioning. The problem should be solved with the replacement of it. If the wire is missing, it’s a good idea to get one fitted properly.

Improper Placement

It’s possible to cause this problem by placing the thermostat in an inappropriate location. If it is near an air vent, the cool air will make the thermostat register the room as already cool. 

If the room is close to a window, the thermostat will register it as warm. If you want to keep it away from a window, you should consider keeping it away from air vents. It is possible that the thermostat is malfunctioning and would need a replacement.

Low Batteries

The thermostat screen can be faded or blank, which is an indication that the thermostat’s batteries are running low. Replacement of the batteries is recommended in such cases.

Reset Problem

This usually happens when the thermostat is disconnected from the internet. To fix the issue, you will need to do a full reset.

The Nest Thermostat Keeps Turning On The Air Conditioning. Why?

If the thermostat is shorted, if the temperature setting is incorrect, or if the wiring hasn’t been done properly, the thermostat will keep turning the AC on. Incorrect temperature setting is the cause of the Thermostat being shorted.

Thermostat Is Shorted

You can check for continuity by testing the thermostat with a multimeter. If you notice continuity, it means there is a short connection. In this case, you need to get the thermostat replaced.

Incorrect Temperature Setting

It’s possible that the temperature difference between the outside and where your air conditioner is installed could be too high. If the temperature outside is 95 degrees and the temperature where the air conditioner is installed is 65 degrees. 

The thermostat will have to keep the air conditioner running all the time to keep up with the temperature outside. A more reasonable thermostat temperature setting is what you should try.

Defective Unit

Thermostats can malfunction at times, although they rarely run into problems. If you want to know if your thermostat is working well, you should keep a temperature near it for a couple of hours. 

There are chances that the thermostat is malfunctioning if the temperature is close to the home temperature. If you want to have it changed, you can try to get it repaired.

Improper Wiring

If the wiring of the thermostat has been done correctly, you should check it out. Some wires don’t match the colors. Have they changed in some way?

The Nest Thermostat Keeps Turning On The Air Conditioning. Why?

The Home/Away Assist setting isn’t enabled, the Home bridge schedule isn’t on, or the thermostat isn’t set to Eco mode, which causes the Nest thermostat to turn the AC off.

  • Home/Away setting isn’t enabled
  • Home bridge schedule is ON
  • The thermostat isn’t in Eco mode

Home/Away Setting Isn’t Enabled

The thermostat is likely to turn off the AC when the Home/Away setting is not enabled. If you enable this setting along with the Auto-Away setting, the thermostat will identify your location based on your phone’s location data. When you are at home, this will prevent the AC from being turned off.

Home Bridge Schedule ON

When it is not required to do so, it will turn the AC down even if this setting is turned ON. It is a good idea to turn this setting off when you aren’t around.

Thermostat Not In Eco Mode

The thermostat usually turns the AC down if this mode isn’t on. The problem can be solved when this mode is permanently ON.

Rather Than Turning On The Heat, Nest Turns On The Air Conditioning

Nest Thermostat Keeps Turning The AC ON/OFF

The wrong wiring connection could be the reason for the problem. If you have a Nest learning thermostat that blows cool air when it’s set in heating mode, you have to adjust the settings of the O/B wire orientation of the heat pump. This can be accomplished by following the steps given.

Press the ring on the thermostat if you want to access its menu. The ring should be turned around and you should choose settings from the menu.

The equipment option has to be selected. The Continue option needs to be pressed a second time. The choice is between the heat pump and the option.

If you want to use a heat pump, the thermostat should be set to the O orientation. If the O option is selected and the B option is not, choose the B option. To make sure the problem is solved, you need to test the cooling and heating again.

The power connection to the heating and cooling system should be turned off if the above steps do not work. The wire connection to the O/B should be disconnected. The copper wire should be exposed by about one-third to half an inch if the wire is not bent. The wire should be stripped to the desired length if not.

If you want to fit the display, you have to connect the wire back into the thermostat. The power should be turned on and checked for heating and cooling actions.

Why Is My Nest Not Cooling?

Incorrect O/B wire orientation, a bad or bulged Capacitor, a non-working condenser, or if the thermostat is faulty are just some of the reasons that your nest may not be cooling. The O/B wire is not in the right orientation.

How To Fix A Nest That’s Not Cooling

The steps involved in fixing a nest that isn’t cooling depend on the problem. There are some steps that you can try to resolve the issue. The orientation of the O/B wire should be changed. 

This change can be accomplished by following the steps in the section above. It’s a good idea to inspect the thermostat for a malfunctioning condenser.

The problem can be solved with the replacement of a faulty component. An odd noise coming out of the nest or a small amount of cold air coming from the vents are some of the telltale signs of a broken condenser.

If the outdoor unit turns on, it’s time to jump the Y and RH terminal on the thermostat. If that’s the case, the thermostat needs to be replaced. The problem is with the unit if it doesn’t work and you hear a buzz from inside.

Also, check for the power rating when the terminals are jumped. If you don’t see any issues here, you’ll have to look into the wiring as there are chances of incorrect wiring.

Why Is My Nest Not Heating?

A missing C wire, improper O/B wire orientation, or the thermostat being too close to a heat source are some of the reasons your nest might not be heating. Improper O/B wire orientation leads to a Thermostat that is too close to a heat source.

How To Fix A Nest Not Heating

If you follow these steps, you can fix a nest that isn’t heating up. You can reverse the O/B wire orientation by following the steps in the “Nest thermostat turns on AC instead of heat” section.

A wire is needed to connect the AC to the C wire. This will likely help address the problem. If the thermostat is close to a lamp, it’s probably a heat-emitting source. The thermostat could interpret this as a sign that the house is cooler than it is. Repositioning the thermostat to a different location away from the heat source is possible.

The thermostat should be removed from the base. White and red wires need to be disconnected from their base terminals. The two loose ends need to be pulled together tightly. The air conditioning may be malfunctioning if there is no hot air with the short connection. The problem with the thermostat is if you experience hot air.

Nest Turns Off The Air Conditioning Before It Reaches Its Set Temperature

There are two main reasons that the AC is likely to be turned off before it reaches the temperature. These are not the normal ones.

  • Airwave mode
  • Loose connection

The compressor gets turned off if the Nest is set to operate in the Airwave mode, but the fan keeps running and the cooled air is dispersed. The thermostat will turn off the AC in the room if it senses that it is already cool. 

There could be some loose wire connections in the thermostat. The problem can be solved with the identification and tightening of such connections. The chance to check for incorrect wiring is also a good chance.

What Causes The Nest Thermostat To Be 10 Degrees Off?

A resetting problem, a malfunctioning humidity sensor, incorrect setting sunblock, nearby heat sources, or a network connection problem are just some of the reasons why your thermostat is usually 10 degrees off.

  • Resetting problem
  • Malfunctioning humidity sensor
  • Incorrect sunblock setting
  • Nearby heat sources
  • Network connection problem

The following are some ways you can address the above problems.

If you want to reset the thermostat, follow the instructions on the screen and use the Reset option under the settings menu. You will have to hold the display down for 10 to 15 seconds if you press the display. When the logo of the search engine appears on the screen, release the pressing action.

Your thermostat may have an off reading if your humidity sensor isn’t working correctly. It’s possible to get the sensor replaced to help. If the base of your thermostat also needs a replacement, you might want to check that out. Ensure that the Sunblock setting is on by checking it.

Under the Sunblock menu is where you can find this setting. Taking into account the sunlight present in the room, it will take a few days to adjust the room temperature. 

The thermostat should be kept in a different location that is away from heat sources such as appliances, electrical outlets, and air vents with warm air circulation to mention a few.

The thermostat needs to be checked for the network connection. In some cases, the thermostat’s wi-fi chip can get overheated and cause an incorrect ambient temperature reading.

It’s a good idea to take the thermostat out of the network for a day and keep a record of the temperature. The heat generation comes from the wi-fi access point if the temperature goes back to normal.

Nest Thermostat Won’t Turn On The Air Conditioner

If there is a missing C wire, your thermostat might not turn on the air conditioner unit because it is set to Heat mode. Sometimes the system circuit breaker needs to be reset or replaced. There is a missing C wire that needs to be reset for the system circuit breaker.

It is possible to turn on the air conditioning unit with the help of the tips given below. If the thermostat is set to operate in heat mode, you should check that. It should be changed to Cool mode if that is the case. The temperature setting should be lowered to about 5 degrees cooler than the current temperature.

You will usually have to wait for about 5 to 10 minutes for the setting to take effect. It’s most likely that the thermostat isn’t connected to a C wire connection. Most of the time, this connection is not present in most thermostats.

The unit can function more effectively if this is included. If the thermostat has a blown-out fuse or a faulty circuit breaker, you need to check it out. A replacement for the malfunctioning component is recommended.

With Nest, The Ac Fan Won’t Turn Off

The fan schedule setting, a power supply to the system, and a pending thermostat reset are some of the factors that may prevent the fan from turning on. The power supply to the heating and cooling system will be reset pending the thermostat being reset.

You can do the following steps if the AC fan doesn’t turn OFF with a Nest thermostat.

If the fan schedule setting is set to be always on, you should check it. You should consider turning it off if that is the case. If the problem is solved by turning the schedule off and ON again, you can do that.

The power supply to the heating and air conditioning system needs to be disconnected. The problem of the fan not turning on can be solved with this. If you want to restore the factory default settings, you need to reset the thermostat.

This will prevent the fan from being on constantly. The nest needs to be taken out of the wall. The thermostat needs to be changed if you notice that the fan is no longer spinning. There could be an internal furnace or stuck relay issue that needs to be addressed if the spinning continues.

Ac Compressor Does Not Turn On When Nest Thermostat Is Turned On

There are some common reasons why the thermostat won’t turn on the AC compressor, such as a blown-out fuse, compressor lock-up, or Airwave mode. There is a blown-out fuse on the heating and cooling system.

The problem of the thermostat not turning on the AC compressor can be solved by using the tips given below.

If the heating, ventilating, and air conditioning system has a blown-out fuse, it’s a good idea to have a replacement done. If the C wire is inserted into the wrong part, this can happen.

There is a possibility that there is a compressor lockout. Replacing the compressor is a good solution in this situation. If the Airwave option has been turned on, you should check that. If that is the case, turning it off can do the trick. Under the Nest Sense setting, there is an option that can be found.

Short Cycling Of The Ac Caused By Nest Thermostat

A low level of refrigerant, a missing C wire, or a faulty thermostat is some of the factors that can cause the AC to short cycle. The missing C wire thermostat has a low level of refrigerant.

The following tips can help you solve the above issues:

If the AC unit is low on refrigerant, you need to check it out. If that is the case, fill it up to the required level. The compressor can be affected by a refrigerant leak and this is a good time to check it out. The C wire needs to be installed in the correct location.

The short cycling process will be stopped most of the time with this. There is a chance that the thermostat could be malfunctioning. Replacing with a new one may be able to resolve the issue.


Here are some of the problems that may cause the issue: The thermostat isn’t working properly. There are too many people in the home. The thermostat isn’t set correctly. The air conditioning system is malfunctioning. The thermostat is malfunctioning. 

The thermostat isn’t connected to the network. There is a power outage. The thermostat is out of range. There is a power outage. The thermostat is connected to the network.

We hope that this article helped you gain all the information you needed to know “Why Your Nest Thermostat Keeps Turning the AC ON/OFF”. Thanks for reading!

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Reggie Burton is a technology expert with over nine years of experience in the field. He has worked extensively with both large and small businesses to help them optimize their tech infrastructure and improve their overall efficiency. Reggie is known for his calm demeanor and his ability to quickly assess a situation and find a solution. He is an invaluable member of any team, and his clients are some of the most satisfied in the business.

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