Common Scenarios when the Nest Thermostat Does not Cool
Firmware update: A problem is observed across various generations and variants of Nest thermostats, where the thermostat or app may indicate cooling or precooling, but instead, hot air is being released from the unit. This issue can be triggered by a firmware update, causing a previously functional Nest thermostat to stop cooling. Air conditioning option not shown: Some people may find that only the heating option is available on the thermostat, and the AC unit is not shown as a cooling choice. This problem is not limited to specific types of equipment, as it occurs with various manufacturers, including heat pumps, AC units, gas or electric systems, and forced air systems. Only the heating option works or the thermostat goes offline: Interestingly, in certain cases, the heating option functions correctly despite the cooling problem. Customers have reported instances where the AC power turns on briefly and then switches off. Additionally, there are occurrences where the thermostat goes offline. The problem may arise with both new installations and previously well-functioning thermostats. Some people have experienced this issue after switching the thermostat from heat mode to cool mode after a season change.
Troubleshooting Pre-requisites
Make sure none of the circuit breakers in your setup has tripped.Check if increasing or decreasing the temperature impacts the cooling.
How to Fix Nest Thermostat Not Cooling?
If you are indeed experiencing a hardware problem and your device is non-functional, you will have to ultimately either claim a warranty or get it replaced. In case of bugs & glitches that might be limiting your cooling, here are some steps you can take.
1. Restart the Nest Thermostat and Equipment
The Nest thermostat will not send a required cooling signal to the cooling unit if the thermostat modules are in an error state. Resultantly, the cooling unit will not power on and thus will not cool the air. To address this issue, restart the Nest Thermostat and your equipment.
2. Verify the Wiring Configurations
If the wiring configurations on the Nest thermostat are not properly verified, the thermostat won’t be able to authenticate whether it can control the cooling unit. As a result, it will not send the necessary powering-on signal to activate the cooling system. In such a case, verifying your wiring configurations on the thermostat will do the trick.
3. Change the Orientation Settings of the Heat Pump
The heat pump utilizes a reversing valve to alternate between hot and cool modes. The OB setting, also known as the Orientation setting, allows you to configure the heat pump type on the thermostat. If your cooling system is blowing out warm air when you’ve set the Nest thermostat to cool, it indicates an incorrect orientation setting. Here, changing the orientation setting on the Nest thermostat will rectify the issue.
4. Reset Your Schedule to the Defaults
If the learned or manually created schedule of the thermostat becomes invalid, it will be unable to send the cooling signal to the cooling system, resulting in the cooling issue at hand. In this situation, resetting the schedule back to its default settings will solve the problem.
5. Disable Home-Away Assist
The Home-Away Assist feature enables the thermostat to cool the area when you are present or about to arrive, and it reduces cooling when you are away to save energy. However, if there is a malfunction in the location modules of your phone, the thermostat will not detect your presence at home and consequently fail to activate the cooling. To address this issue, disable the Home-Away Assist feature. This way, the thermostat won’t rely on your phone’s location and will follow a different cooling pattern.
6. Disable Auto-Schedule
The Nest thermostat utilizes the Auto Schedule feature to automatically cool down your home based on your daily routine. However, if you deviate from your regular schedule or the Auto Schedule feature malfunctions, the cooling system will cease to function properly. This can be fixed by disabling Auto Schedule.
7. Disable Safety Temperature
To prevent your home pipes from freezing or your home from overheating, the Nest thermostat comes equipped with the Safety Temperatures feature. This feature ensures that the thermostat will activate or deactivate cooling or heating, even if the thermostat is off when your home reaches a specific temperature threshold. However, we’ve seen issues where this safety feature fails to initialize property and as a result, cooling doesn’t happen. To solve this problem, disable the Safety Temperature feature on the thermostat.
8. Reset the Nest Thermostat to the Factory Defaults
If the core firmware modules of the Nest Thermostat are damaged, the unit will be unable to initialize cooling, leading to a lack of cool air from your cooling system. To rectify this issue, perform a factory reset on the Nest Thermostat. Be aware that this action will erase any learned patterns or schedules that the thermostat has accumulated. If you wish to preserve the current configurations or wiring, access the thermostat’s Settings and navigate to Equipment to make a note of them beforehand.
9. Reinstall the Nest or Google Home App
The Nest thermostat is tightly linked to the Nest app. If the latest update installation has damaged the core components of the app, the app will fail to convey the required commands to the thermostat properly and thus cause the issue. Reinstalling the Nest app after resetting the Nest thermostat will get the job done.
10. Connect the C or Common Wire
Until now, we were trying to solve the problem on a software basis but now, we have to get our hands dirty. The last step in troubleshooting a cooling issue when using a Nest thermostat is checking and correcting its wiring. But as that is too specific in each case, we will just be limited to connecting the C or common wire. We will exclusively focus on providing general guidelines for connecting the C wire, as they can vary depending on the specific products and equipment involved. To ensure successful implementation in your unique scenario, you may need to conduct further research and dig deeper into the details. If the issue is still there and another thermostat is available with you, replace the problematic Nest thermostat with it and see if the cooling problem is solved. If the cooling starts to work, then the thermostat is faulty, otherwise, the issue lies in your equipment. If you identify that the problem is related to the thermostat but it is out of warranty, check its terminals for any visible damage. If it is under warranty, contact Google Support and request a replacement. The support may guide you on the wiring and you may need to ensure your setup meets those instructions. If the issue is equipment related, then there can be various causes for this, such as a blown capacitor in the fan unit, a blocked drainage pipe, converter issues in the HVAC unit, or problems with pressure within the unit, etc. and you will need the help of repair service to identify and rectify it. If the issue is due to pressure in the unit, make sure there is no leakage in your cooling or heating system before refilling it.
