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Ecobee3 lite Troubleshooting - PartsXP

ecobee3 lite troubleshooting

Ecobee3 Lite smart thermostat is very reliable. However, with many technologies, sometimes it will stop working or won't turn on. Power issues can be caused by many reasons. Follow the steps below if you are having problems with the thermostat turn on. Whether you have a new Ecobee3 lite smart thermostat or an existing one that stopped working, here, you can get Ecobee3 Lite troubleshooting steps.

Ecobee3 Lite Troubleshooting Guide

Here are basic steps which you need to follow in detail when your Ecobee Lite doesn't turn on.

Ecobee3 Lite Thermostat Won’t Turn ON

There are a few steps that you do to fix the power problems to your Ecobee3 lite smart thermostat. Get the troubleshooting steps for a newly installed thermostat or for a thermostat that is previously worked.

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Troubleshooting Guide for Newly Installed Ecobee Thermostats

Try the potential solutions given below if you are having trouble with the newly installed Ecobee.

Is there a C wire?

The Ecobee requires a C wire to power on. So, you should have a wire connected to the C terminal of the thermostat. If you don't have a C wire, check that your thermostat bundle for spare wires that may be possible to use any wire as a C wire. Moreover, your chosen wire must be connected to the C terminal on your HVAC control board before using it as C.

If you didn't found any spare wire, but have R, G and Y labeled wires, then you will have to install the Power Extender Kit (PEK). If you have done this process, but the thermostat doesn't power on, just go through the next troubleshooting step.

Did you install Power Extender Kit (PEK)?

In some heating systems, Ecobee3 lite needed a power extender kit. If still, your thermostat does not power up even after PEK installation, you should check the wiring. The wiring has to be configured as follows:

  • R wire to RC terminal.
  • W Wire to W1 terminal.
  • G wire to the C terminal.
  • Y wire to PEK terminal.

If you have installed PEK, the C wire coming off from the kit should be connected to the C terminal on the HVAC system control board.

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Is Ecobee placed correctly on backplate?

You have to verify that your ecobee is seated properly on the backplate.

At certain times, the thermostat wires prevent the ecobee from connecting to the backplate and cause the thermostat not to power on. You have to push back thermostat wires to allow thermostat pins to insert completely into the backplate.

Make sure the connected wires on the backplate are not stopping the thermostat from making correct contact. Check if the thermostat has been fully inserted by inspecting spaces between ecobee and backplate. You can hear a click sound when ecobee connects to the backplate properly.

Check for voltage

If no issues with the wiring and all wiring as it should be, then there might be an issue with the voltage. You can test the voltage yourself if you have a voltmeter. Test the voltage between Rc and C wires with a voltmeter. The voltage between these two terminals should be 24 VAC. If it is less than 24 VAC, the thermostat will not power up.

If there is no voltage or less than 24 VAC, you need to check the following:

  • Be sure that the power is turned on at the circuit breaker.
  • Some HVAC systems have a safety switch that may cut off power to the unit if its cover panel is not closed properly or opened. Hence, the cover panel of the equipment should be closed correctly.
  • Inspect the 3 amp or 5 amp fuse on the furnace control board. If the fuse is blown, you have to replace it.
  • If you have installed PEK, check for a short circuit on the C wire. When there is a C wire short, you can hear a clicking sound. Try to resolve the problem by using another wire as a C wire.

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Troubleshooting Guide for Ecobee3 Lite that was Previously Working

Is your thermostat suddenly stopped? It indicates that there is a power failure between the thermostat and your HVAC furnace. When insufficient voltage going to the thermostat, you will notice a black screen all of sudden. Ecobee receives power from the furnace so that any disruption to the power source will result in a loss of power at the thermostat.

Test the voltage with a voltmeter between Rc and C terminals. Less than 24 VAC is not sufficient to power on. Also, check for the following:

Tripped Circuit

To know that the circuit powering the furnace is not activated, you have to search your breaker box. If it is tripped, switch it back on to restore power to the furnace. Then, ecobee3 lite should power back on.

Blown fuse on the furnace control board

Open the control panel on your furnace to expose the control panel where your thermostat wires are connected. Most systems have an orange 5 amp or purple 3 amp fuse on the board. The fuse should be intact. If the fuse has blown, it needs to be replaced. After a blown fuse replacement, your ecobee should power back on.

Tripped high limit temperature sensor

This is usually occurred by rebooting at the thermostat during a call for heat which may also result in a total lack of thermostat control.

Tripped float switch

Inspect if there is excess water on the furnace's float switch, drip pan, or condensation pump. If there is any excess water or blockage, it will prevent the water from draining. Once, you cleared this, your ecobee might get power back on.

Final Words

Hopefully, one of the above steps fixes your Ecobee not powering on. If none of the above Ecobee3 Lite troubleshooting steps worked and your ecobee is not turning on still, there is a fault with the equipment itself. For further more assistance, you can contact ecobee support.

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