Nest Thermostat Off But Heating On: How to Troubleshoot

If your Nest thermostat is turned off but heating on, here are some reasons this might be happening:

  • Your heating system is still turned on.
  • You installed your thermostat in an inappropriate location.
  • The thermostat’s switch wires are malfunctioning.
  • Your heating system is not compatible with your thermostat.
  • Your thermostat isn’t getting enough power.
  • The thermostat’s firmware is outdated.

Keep reading to learn how to troubleshoot this problem.

Nest Thermostat Off But Heating On

Nest Thermostat Off But Heating On: Try These Troubleshooting Steps

1. Check the Location of Your Nest Thermostat

Your Nest thermostat may develop issues if you just place it anywhere. The device is best installed away from areas where extreme sunlight or other unusual temperature conditions can affect it.

If your thermostat is located near a window or the entry of a hallway, the device may keep heating even when turned off. This is because it is exposed to sunlight—which increases its temperature.

Move your thermostat from an exposed area to your living room or dining room. These locations often retain room temperature, so your thermostat is less likely to heat while off.

If your Nest thermostat keeps heating after you’ve moved it to a cool place, continue to the next step.

2. Lower Your Thermostat’s Temperature Settings

Sometimes, your heating system may stay on after you’ve switched off your thermostat. As a result, your thermostat will keep heating.

To troubleshoot this issue, switch on your Nest thermostat and reduce the temperature setting. Now, wait a few minutes for the device to respond to your action.

If your Nest thermostat automatically increases its temperature setting after a few minutes, the device is working fine. Turn off the switch on your heating system. Then turn off your thermostat.

However, if your thermostat stops heating when you reduce its temperature settings, the device is faulty. Resetting your device should resolve this problem.

Here’s how to reset your Nest thermostat:

  • Press the ring in your thermostat to open the Quick Menu.
  • Next, turn the ring to Settings to select the option.
  • Press the ring again to select Reset.
  • Tap All Settings. Then push the ring to reset your thermostat.

After resetting your thermostat, switch it off and wait for a few minutes. If the device starts heating again, check the next tip.

3. Remove Your Thermostat’s Switch Wires from Your Heating System

Two of your Nest thermostat’s wires are connected to your heating system. These wires are your thermostat’s switch wires, and they cause the thermostat to increase its temperature settings when the temperature in your room falls.

When you turn off your thermostat, these wires should stop working. But if your thermostat is still heating when you turn it off, its switch wires might still be functioning.

You can quickly fix this issue by detaching your thermostat’s switch wires from your heating system. Re-attach these wires to your heating system when you need to switch on your thermostat again.

Locate your thermostat’s switch wires at the control for your heating system. Your switch wires are the white and red wires connected to the T1 and T2 terminals on your heating system.

What if your Nest thermostat keeps heating after you’ve removed your thermostat’s switch wires? If this happens, proceed to the next step.

4. Check if Your Nest Thermostat is Compatible with Your Heating System

If your Nest thermostat is incompatible with your heating system, it might work properly for a while. But after some time, the thermostat will start malfunctioning.

To fix this problem, you’ll need to check if your thermostat is compatible with your heating system. The Nest thermostat supports most heating systems except high-voltage, solid-fuel, and proprietary systems.

A high-voltage system is a heating system that requires high amounts of volts to function. If your heating system uses about 110v, it is a high voltage system. One good example of a high-voltage system is an electric floor heater.

In contrast, proprietary systems are heating systems that only work with thermostats produced by the same manufacturer. Solid fuel systems use wood or charcoal to generate heat, which they then circulate around a house with a pump.

If your thermostat does not support your heating system, you’ll need to replace it with a compatible alternative. You can re-install your old thermostat while trying to purchase a new one.

If you don’t have an old thermostat, you can try using a C-wire to connect the heating system to your thermostat. Your thermostat may stop heating when you do this.

If your heating system is neither high-voltage, solid fuel, or proprietary, it is probably compatible with your thermostat. In that case, move on to the next step.

5. Insert a C-wire into the Thermostat

If your thermostat keeps heating after you’ve turned it off, the device might not be getting enough power. The lack of sufficient power may cause functional issues in the thermostat.

To ensure that your nest thermostat gets enough power, you’ll need to insert a C-wire into the device. A C-wire will transmit extra power from your circuit board into your thermostat.

You should find your C-wire in the C-terminal in your circuit board. If you can’t find a C-wire on your circuit board, ask an electrician to install the wire.

Once your Nest thermostat gets enough power, it should stop heating. But if the device keeps heating, try the next tip.

6. Update Your Thermostat’s Firmware

Another reason your Nest thermostat may keep heating after you’ve switched it off is outdated firmware.

You can fix this issue by updating the thermostat’s firmware.

Take the following steps to update your Nest thermostat’s firmware:

  • Click on the Mode option on your thermostat’s screen.
  • Next, turn your Mode to Off.
  • Go back to the home screen. Then click on Settings.
  • Now, select Version. Then tap Update to update your thermostat’s firmware to the latest version.

Once you’ve updated your thermostat’s firmware, the device should stop heating. However, if the thermostat is still heating, check out the next tip.

7. Ask Your HVAC Technician to Service Your Thermostat

Your Nest thermostat won’t work properly if you don’t maintain it regularly. So, if your Nest thermostat keeps heating even when it is turned off, you might need to service it to fix the problem.

Get a trained HVAC expert to service your thermostat.

But first, you want to confirm that your thermostat actually needs maintenance before calling your technician. After all, you don’t want to spend extra cash on solving an issue you could fix on your own.

You can check if your thermostat needs maintenance by restarting the device.

Follow these steps to restart your thermostat:

  • Flip off your circuit breaker.
  • Wait for about 5 minutes to let your thermostat rest.
  • Now turn on the breaker.

If restarting the thermostat does not stop the device from heating, you might not need to service the device yet. However, if the thermostat stops heating after restarting it, then it starts getting hot again, the device needs servicing.

Ask your technician to inspect and fix the thermostat.

If your thermostat keeps heating after this, contact the Nest Support team. If your thermostat is still within its warranty, the team may repair your device without charging you.

Wrapping Up

If your Nest thermostat is turned off but heating on, move the device to an appropriate location. Then lower your thermostat’s temperature settings. You might also need to remove your thermostat’s switch wires from your heating system.

If the thermostat keeps heating, check if the device is compatible with your heating system. Another way to fix this issue is to insert a C-wire into the thermostat and update the device’s firmware.

You can also ask your technician to service your Nest thermostat.

However, if your thermostat is still heating after you’ve tried all these tips, contact Nest Support for help.

You may also like to see how to troubleshoot heating and cooling issues in Wyze and Honeywell thermostats.