Troubleshooting

My screen is blank (Sensi Touch, Touch 2)

If you installed a Sensi Touch or Touch 2 smart thermostat, but the touchscreen is still blank after completing all the steps in the Sensi app, then most likely the thermostat is not receiving enough power from your system to turn on.

Sensi Touch smart thermostat has a battery powered light in the sub-base for installation, but that light will only last for about an hour, and is not an indicator that there is power to the thermostat. Sensi Touch 2 smart thermostat does not have any light or battery. Both touch models require a “C” wire to provide 20-30VAC to power the thermostat. Without system power, both touchscreen models will not turn on.

Do you have a wire in the “C” terminal?

Sensi requires a “C” wire. If you don’t have a wire in the “C” terminal, you’ll need one. Check out our “C” wire videos for DIY installation.

If you are installing Sensi to a heat only system, you may be able to install an external transformer. Learn more about that option here.

I have a wire in the “C” terminal.

1. Did you DIY this “C” wire connection? If so, make sure that this wire is connected to “C” terminal at the thermostat and at your system.
   1. Go down to your air handler, reveal your system’s control board, and trace the “C” wire to ensure that it is securely connected to the “C” terminal at the control board. If you haven’t already, it may help to watch one of the "C" wire videos to see how to access the control board.
   2. Gently tug the “C” wire at the system control board to ensure that it is screwed into the terminal securely.
   3. Gently tug all the wires at the thermostat to ensure that they are secure in the terminal block on the sub-base.
2. Do you have a voltmeter? Set your voltmeter to AC and measure the voltage between RH (or RC) and C at the thermostat to ensure that you have between 20-30VAC at the thermostat. If you have less than 20VAC, the thermostat will not turn on.
3. Are your breakers on? You turned your power off for installation. Make sure the power is turned on. You may want to try resetting them if they’re turned on already.

I have already installed Sensi, and I have a wire in the “C” terminal.

Both touchscreen models do not have battery back-up. If power is lost from your system due to a power outage or system issue, the screen will go blank and will become unresponsive.

1. Is your power on?
2. Have you tried resetting your breakers?
3. Ensure that all panels to your HVAC system are shut and secure.
4. Do you have a back-up thermostat that you could install to test your heating and cooling operation? If there is any issue with your system, power may be lost to the thermostat.
5. If you don’t have a back-up thermostat to install, do you have a voltmeter? Set your voltmeter to AC and measure the voltage between RH (or RC) and C at the thermostat to ensure that you have between 20-30VAC at the thermostat. If you have less than 20VAC, the thermostat will not turn on.
6. Remove the thermostat face plate and ensure that there are no bent pins on the Sensi Touch sub-base, above the bubble level.