Installing a Cync Thermostat

Follow the steps outlined in the Cync application or in the Installation Guide that is included with your Cync Thermostat.

IMPORTANT:

• Power off your circuit breaker and ensure that all equipment is fully powered off.
• Do not proceed if voltage labels read 110v or 120v, L1 or L2 terminals are present, or high voltage warnings are present.
• Confirm your wiring is compatible with the Cync Smart Thermostat by using the Cync Thermostat Compatibility Tool.

Troubleshooting

There is an extra wire in the wall after removing the old thermostat.

The extra wire is called the C-wire, and is used to power on the Cync thermostat. Because this wire is present you will not need to use the Power Extender Kit (PEK) during installation.

The C-wire is not present in the wall after removing the old thermostat.

The C-wire is required to power on the Cync thermostat. Because this is not present you will need to use the Power Extender Kit (PEK). See the wiring diagram below on how to install the PEK.


NOTE: No need for a jumper wire between RC and RH. The thermostat will handle it for you. The R wire needs to go into the RC terminal on your thermostat.

My thermostat will not power on following installation.

• Confirm that all wires are properly inserted into the terminal blocks at the thermostat. Tug at the wires to ensure they are firmly in place.
• Make sure the R (power) wire is connected to the RC terminal.
• Ensure the circuit breaker is powered back on.
• Some HVAC equipment feature a safety or locking system that cuts power off if the cover panel isn’t shut properly. Ensure that it is.
• If the Power Extender Kit (PEK) was used, ensure the R wire is connected to RC only. Confirm that the G wire is inserted properly into the terminal.

The thermostat has been connected to a dehumidifier, humidifier or vent but doesn't appear to be working.

The Cync thermostat is not compatible with dehumidifiers, humidifiers and vents.