Nest Thermostat E Troubleshooting

• If your thermostat shows a low battery alert, change the batteries first so that you can control your system and stay comfortable while you troubleshoot.
• If you recently turned the power off at the circuit breaker of the heating and cooling system, make sure it’s back on.
• If you were installing the Nest Power Connector and there's an N260 help code, confirm that the cover is closed on your HVAC equipment. There is often a safety switch that prevents operation with the cover removed.

• This code can only be found on the thermostat meaning the app cannot be used to know if this code appears

• The Nest Thermostat E  will display a message that states it is not able to connect to Wi-Fi. This message will end with “nest.com/w5”

• The thermostat’s Network menu can be checked to make sure that the W5 code has occurred

To do this:

1. Push on the thermostat to open the Quick View Menu
2. Select the Settings menu
3. Turn the thermostat all the way through until the Network button occurs.
   • One of these messages may occur

“Error - nest.com/w5.” This is a W5 code***

• The name of your Wi-Fi network. This is not a W5 code
  • “Not connected.” This is not a W5 code

You will need to restart your thermostat

Try the steps in the troubleshooting Google guide listed below:

• Troubleshoot Wi-Fi and connection issues 

Your Nest Thermostat E does not lose any customized information or the settings that you entered if you were to restart the thermostat.

Once the Nest Thermostat E restarts you can continue to use it as it was used before

1. Push on the thermostat to open the Quick View Menu
2. Select the Settings menu
3. Click Reset
4. Click Restart
5. Once the thermostat restarts, you can try to reconnect it to your Wi-Fi
   • On the thermostat, go to Settings and then click Network and then select the name of your Wi-Fi network

1. The first step is to make sure that the Nest thermostat is powered on and Nest is receiving power.
2. If the code persists, move your phone closer to the thermostat.
3. If the error code persists, reset the account that is linked to the thermostat. Note: Make sure you do a reset connection and not a factory reset of the device. Please view this link for more details.

If your Nest thermostat is displaying a “no power” alert, this means it is not receiving power from your HVAC system.  Your thermostat may display one of the following:

• “No power” or “No system power”
• Help codes M20 or E298

Codes can be dismissed but may reappear if the problem persists.

The setting icon will appear with an exclamation point above it.  When hovered over, it will display the phrase “equipment error.”

“Low battery or “very low battery” alerts may appear if the backup batteries continue to lose charge.

Your thermostat may disconnect wifi when power is not being received.  This can still occur even when the battery power is good.

A “No power” alert can be caused by the following:

Check the device wiring schematic for any wires that appear grayed out.  A wire appearing gray means that the wire is not currently sending proper voltage to your device or may not be properly entered into the app.  Some wires like the C or R wires need to send constant voltage to keep your thermostat fully powered.

Important: The device must be powered off before checking the system wires. This helps to prevent damage to the wires,  your thermostat, and/or your HVAC system.

• Turn off the power for the system in the circuit breakers, fuse box, or system switch.
  • Some HVAC systems may have one switch for heating and one for cooling, or a single switch for both heating and cooling.  Ensure both are in the “off” position.
• Remove your thermostat from the wall by the base.
• Ensure the wires are properly connected using this guide.
  • If rewiring is required:
    • Push down on the connector tab and gently pull the wire out
    • Re-straighten the end of the wire
    • Strip wire to ensure  ⅓" to ½" of copper is exposed
    • Fully reseat the wire into the proper connector
  • After the wires are re-connected, re-attach your thermostat
  • Turn the system power back on
  • Wait a few moments.  Then, go to the thermostat menu>equipment>, and ensure everything is now working properly.

The device is connected to a system that requires a c wire (common wire) connection, however, the wire is not connected to the device.  Some HVAC systems, including heat-only, cool-only, zone-controlled, and heat pump systems, may require a C wire, or “Nest Power Connector.”  Visit g.co/nest/wire for more details.

The HVAC system may be powered off due to a flipped breaker, blown fuse, or system switch.  Check your circuit breaker, fuse box, or system switch to ensure they are working properly.  A power cut may also cause a loss of system power.

The HVAC system may have some other technical issues that are preventing power from being sent to the thermostat wires.

Some steps to troubleshoot the “no power” alert on your thermostat can include:

The following article only applies to the Nest Thermostat device.

If your Nest device won’t turn on, or if your device is having power issues, learn how to troubleshoot when your Nest thermostat won’t turn on here.

If condensate water cannot exit system due to PVC pipe blockage it will collect in Drip Pan under indoor unit eventually tripping a sensor that will turn off power. Find and clear blockage and drain pan.

In some cases there is a Condensate pump that collects water and pumps it out. Occasionally this pump fails or is unable to pump water out due to blockage or power issues. The filled pump will trip a sensor that will turn off power. Inspect pump is working correctly and not filled completely with water.

If you didn't see a code, your thermostat will show you a link to let you know which wire you need to check. For example, if you see "g.co/nest/needWY" you must check your W or Y wire.

You'll see this code if the wires in your thermostat weren't configured properly in the Home app. You'll need to reset your thermostat to the factory default and add it back to the Home app.

If you want to know what each wire does follow this link.

Open up the google nest app

1. Once open, touch and hold your device’s tile
2. Open the settings. The setting is this icon.
3. Select the thermostat you want.
4. Tap “wiring.” This will give the configurations of the thermostat wire.
5. To update the wiring, tap “update wiring.” You’ll want to read through the info before going to the next step.
6. Follow the instructions on the app to update the thermostat’s wires.
7. Note: Pay attention to instructions regarding how to handle the system or consider turning your system power off when dealing with the wires.
8. After updating the wire, test the system to make sure it is working correctly. Remember to turn on the system if turned off.

1. Open the google nest home screen
2. Touch and hold your device’s tile
3. At the top right, tap the setting. This is what the settings symbol looks like.
4. Tap “Remove device” and then click “Remove.”
5. On the thermostat, click on the right side of the thermostat screen. A menu will appear.
6. Swipe to “settings”  and tap open.
7. Scroll to the factory reset.
8. Choose the reset and tap the screen.
9. Select “Yes” and tap.
10. Add the thermostat back on the home app. Tap “Add +” at the top left of the home screen and follow the instructions on the screen. Pay close attention to the instructions when you reenter your wiring information.

If it is still not working, check that the system's wires are connected to the right connectors. Use the wiring diagram the app gave you during setup to move the wire to the right connectors.

If you do not have the wiring diagram, refer to the picture of your thermostat wires that you took when it was installed.  If you did not take a picture, follow these instructions to access your system control board and take a picture of the wires. Use this picture to enter the wires into the app.

1. Open the home app
2. Tap “Add +” at the top left of the home screen
3. Tap “Set Up Device” and follow the app instructions until you reach the wiring step. Use the picture of your old thermostat wiring to enter the wires into the app.
4. Move the wires to the right connectors to match the wiring diagram.
5. Make sure that power is turned off to the system at the breaker box, fuse box, or system switch before moving the wires.
6. Make sure wires have ⅓ to ½ inch of copper exposed. Also making sure the wire is fully inserted into the connector, and that the wire connector button stays down
7. Replace the thermostat display and turn the system’s power back on.
8. Turn the power to your system back on at the breaker or fuse box.

When this code occurs, the first step that you should take is to check your Nest Thermostat E for a C wire. Please see this attached video for more information.

You can check your Nest Thermostat E for a C wire yourself, or contact a pro who can do this for you.

1. Turn off all power to your home at the breaker box, fuse box, or system switch.
2. Pull off the Nest Thermostat E display and check the C connector.

If there isn't a wire: continue to "Check your system for a spare wire"

If there is a wire in the C connector: check to make sure that the wire has the C wire label, after this make sure that the wire is in all the way and the connector button is down

• You may need to strip the wire ends.
  • There should be ⅓ to ½ inch of straight copper wire exposed.

After this, put the thermostat display back on and push until it clicks into place.

• Then turn the power to your system back on.
• Please see this link for more information on the C wire.

Your HVAC system may have a spare wire that is not connected to your thermostat that you may be able to use as a C wire.

IMPORTANT:: These next steps are advanced troubleshooting steps. Your HVAC system uses high voltage, which can be dangerous. If you need to open your HVAC system, be careful not to touch any of the components unless instructed to do so.

If you had a professional installation when you first installed your thermostat, you may want to contact your installer or find a local pro if you need any help before proceeding to the next steps.

1. Make sure to turn off the power to your HVAC system at the breaker box, fuse box, or system switch, if it is not off already.
2. If you find a spare wire, write down the color of the wire.
3. On your HVAC system, look for a removable access panel. This may have a handle or latch, or you may need to remove some screws.
4. Be careful not to touch any of the components inside your system except for the system wires. Some HVAC equipment has electrical components that store a charge like a battery.
5. Check the system board's C terminal. If there is no wire in it, look for the spare wire you found on the thermostat end and connect it to the board's C terminal.
6. Replace the access panel.
7. At your thermostat, connect the spare wire to the C connector. Ensure it is in all the way and the connector button is down.
8. Press the Nest Thermostat E display onto the base until it clicks into place and turn your system power back on

If there is no spare wire, you will need to contact a pro to have one installed.

The most common issue that causes the E73 error is improper or unsecured connections.

You can check your wiring by following the steps below:

1. Disconnect your HVAC system from power by turning off your breaker. Your HVAC system might have multiple breakers throughout the circuit, so ensure all of them are turned off.
2. Detach your thermostat’s display from the base to reveal the wires connected to it. Disconnect the Rc wire while maintaining all the other wires as they were, switching the thermostat to heat-only mode.
3. Remove the Rc wire and examine it. Ensure that it has at least 1 mm of copper exposed and that the copper is not bent. Make sure the wire isn’t corroded or painted over.
4. Using a voltmeter, test the Rc wire to check that the voltage across the wire is consistent. A 24 VAC voltage indicates that your wiring is fine and that the problem is within the AC unit itself. This is common as a lot of AC units fail during the summer due to hotter temperatures.
5. Insert the wire back into the Nest connector while ensuring that the connector button stays pressed down.
6. To be thorough, you can perform the same checks on the other wires as well.
7. Turn your breaker back on to bring back the power.
8. Insert the Nest thermostat back into the base and wait for it to power back up.
9. If C wire is already connected to the furnace, fish the wire out of the wall and connect it to the Nest device
10. If your furnace has a 4-wire set-up, you can purchase a 5-wire adapter from Amazon to then plug into the control board.  This can then be connected to the Nest E thermostat. See this attachment for a Nest wire accessory kit.

1. If the W5 error code still appears, contact Google Nest customer support to help fix this issue
   • You will need to have the help code and your Nest Thermostat E’s serial number before you call so that you can give it to the support agent when you call
   • To find the serial number of your Nest Thermostat E, you will need to pull off the base of the thermostat and flip it over. The serial number will be above the QR code on the back of the thermostat display
   • When you talk to an agent you will need to let them know that you have tried all of the troubleshooting steps above
2. If the W5 code is no longer there but you are still having trouble connecting to Wi-Fi, you can try the steps in Troubleshoot Wi-Fi and connection issues guide, but before you do this, you should contact Google Nest customer support to help with troubleshooting

If you have completed all of the troubleshooting steps above and you are still experiencing difficulties, contact a local HVAC technician for assistance.