Why is Nest Thermostat Blowing Hot Air on Cool? (Quick Fix)

Wondering why Nest thermostat blowing hot air on cool? Here’s the complete solution!

Well, based on the type of system you have and the utilized equipment, there could be many factors influencing the heating/cooling behavior of the thermostat.

This sounds like a simple issue caused by misconfigured thermostat settings, so let’s unveil all the underlying details!

“Nest blowing hot air on ‘COOL’ setting could indicate AC or HVAC system issues, misconfigured thermostat settings, or heat pump problems.”

Let’s learn how to fix the issue.

Why is Nest Thermostat Blowing Hot on Cool?

There are two types of installations compatible with your Nest thermostat that can utilize household cooling and heating.

Generally, most users tend to use a conventional HVAC system with Nest, but you could also utilize a heat pump for both heating and cooling.

Conventional HVAC Vs. Heat Pump?

Whilst a heat pump utilizes both heating and cooling, a conventional HVAC system that consists of ACs requires a furnace in order to also produce heating and cooling.

Thus, a heat pump is a more expensive but reliable choice when it comes down to heating and cooling altogether.

In conclusion, a standalone conventional HVAC system can only cool via the ACs, unless a furnace is installed and connected to the thermostat system.

The Nest thermostat could be particularly producing hot air on the “Cool” setting if there’s an issue with the AC in the home!

Why Does Nest Thermostat Blow HOT on “COOL”?
HVAC Installation System	Heat Pump Installation
Misconfigured thermostat settings	Poor heat pump wiring setup
An HVAC furnace connection throttle	Nest software misconfiguration
A tripped HVAC emergency switch	Damaged or faulty heat pump
HVAC furnace utilization failure	Incorrect pump installation.
Unfunctional or faulty AC units	Improper weather conditions

Google Nest Thermostat Blowing Hot Air On Cool (HVAC)

1. Power Cycle the HVAC AC Units

The primary reason why Nest keeps producing hot air while set on the “Cool” setting is that one or more of your AC devices are inactive.

To correct this problem, you must inspect the power supply of each AC in your system individually and make sure they are working and connected.

How to Power Cycle an AC Unit?

1. Locate the power button on the AC unit.
2. Then, hold the button for 10-15 seconds.
3. Next, unplug the power cable of the AC.
4. Then simply wait for about 60 seconds.
5. Finally, reconnect the cable of your AC.

Repeat the steps above for every AC unit added to your HVAC system. In the meantime, inspect the wiring and physical condition of the AC units and replace any damaged cables.

Note: The power cycle also helps with overheating issues with the AC units!

2. Adjust the Nest Temperature Mode!

You might have accidentally set the thermostat to “Heat • Cool” mode, resulting in constant changes in the indoor temperature.

Within the Nest app, you are able to access advanced heating/cooling settings for the thermostat and elevate the temperature as you’d like.

Note: Make sure you have the Nest app installed on your mobile device before proceeding!

Here’s how to adjust the temperature mode of the Nest thermostat:

1. First, open the Nest app on your mobile device.
2. Tap on the Nest thermostat from the home page.
3. Then simply navigate to “Temperature Settings”.
4. Finally, make sure the thermostat is set to “COOL”.

Info: The thermostat will both produce heat and cool on the combined temperature mode!

3. Correct the Nest Thermostat’s Wiring

Improperly connected cables could also result in issues with the heating/cooling setting of the Nest thermostat.

In an AC/furnace configuration, there are plenty of important cables such as the “C” wire that must be connected to the appropriate terminal for the basic functionality.

• To access the cable configuration section of the Nest thermostat, remove the front panel by removing the holding screws.

Correct Cable Installment for Nest Thermostat?

Here is the correct cable installment for your Nest thermostat:

• The yellow wire must connect with the “Y1” terminal.
• The gray wire must connect with the “Y2” terminal.
• The green wire must connect with the “G” terminal.
• The orange wire must connect with the “OB” terminal.
• The red wire must connect with the “Rc” terminal.
• The brown wire must connect with the “W2 AUX” terminal.
• The blue wire must connect with the “C” terminal.

Info: All cables in the configuration are unique and do not share a color pattern!

4. Inspect the HVAC Furnace for Failure!

Any underlying issues with the HVAC furnace could mess with the Nest thermostat’s heating and cooling mode.

For that purpose, it is recommended to conduct a thorough inspection of the HVAC furnace’s vents, the furnace flame, the gas valve, and other important components.

An HVAC furnace would typically experience one of the following failures:

• Clogged furnace filter surface.
• Failure of the electrical panel.
• A problem with the pilot light.
• An issue with the gas valve.
• Tripped furnace float switch.
• An insufficient furnace flame.

Alert: Any of the following issues with the furnace should be reported to a technician!

Google Nest Thermostat Blowing Hot on Cool (Pump)

1. Adjust the Heat Pump Orientation!

Since the Nest thermostats support heat pump orientation settings, the heating/cooling mode options might have been misplaced.

This could result in the heat pump bringing hot air into the house, while the thermostat is set to conduct the “COOL” schedule.

Here’s how to adjust the orientation settings of the heat pump on the thermostat:

1. On the Nest thermostat, navigate to “Settings”.
2. Then, select the “Equipment” on-screen button.
3. Next, press “Continue” and “Continue” again.
4. On the next page, choose the “Heat Pump” option.
5. Finally, select accordingly:

• If the “O” option is highlighted in the settings, select “B”.
• If the “B” option is highlighted in the settings, select “O”.

Info: The “O” and “B” settings represent the heat/cool orientation of the heat pump system!

2. Hard Reset Your Heat Pump

A simple malfunction with the heat pump could have reverted the heating/cooling regimes of the Nest thermostat.

Such a simple problem can be addressed by conducting a hard reset on the heat pump, which requires disjoining the device from the power supply.

• How to Hard Reset a Heat Pump with a Power Button?

A heat pump that has an in-built power controller (or button) can be hard reset by holding the power button for 30 seconds.

Next, locate the wall switch and turn the controller towards the “OFF” side to deactivate the power supply of the heat pump.

• How to Hard Reset a Heat Pump Without a Power Button?

If your heat pump does not have a power button and neither can you find the wall controller, disengage the power of the device from the circuit breaker.

All heat pumps are wired to the main A/C circuit breaker and have their own power switch within the breaker panel.

Tip: Keep the power to the heat pump deactivated for at least 60 seconds!

3. Verify the Integrity of the Air Handler!

The air handler is an important component in the heat pump setup and it is situated within the household.

The air handler releases the cool/hot air inside of the household and if there’s an underlying issue with any of the valves, the diffuser will not work properly.

So, inspect the air handler’s frontal opening and make sure that hot or cold air is being released into the household.

Also, check the connection of the air handler with the heat pump compressor from the outside to verify that everything works well.

Alert: A malfunction with the air handler should be reported to a technician!

4. Factory Reset the Nest Thermostat

If nothing worked so far, you should perform a factory reset on the Nest thermostat to erase any software-related issues with the device.

In most cases where the indoor or outdoor heat pump equipment isn’t functioning properly, it is due to the Nest thermostat’s system settings.

Here’s how to perform a factory reset on the Nest thermostat:

1. Press the thermostat ring on the display.
2. Open the QuickView thermostat’s menu.
3. Choose the Settings icon from the screen.
4. Next, simply turn the ring and press “Reset”.
5. Finally, choose “All Settings” and confirm.

Alert: All settings, content, and data on the Nest thermostat will be erased after this process!

Quick Recap:

Whenever the Nest thermostat blows hot air on cool, it could be an issue with the heat pump or the conventional HVAC system. To resolve the issue, power cycle all AC units, reset the heat pump’s power supply, and conduct a factory reset on the Nest thermostat.

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