Installation Guide

STEP 4
Take a picture of the wires connected to the
terminals of your old thermostat. You may
need to reference this photo later on.
CHECKPOINT: C WIRE
Do you have a C wire connected to your
old thermostat?
YES
NO
RC RH RC RH
Continue to
Guide 1
Continue to
Guide 2
YES NO
OR
WARNING:
ecobee3 lite is designed for 24VAC with a 2A maximum current.
Do not connect it to line (high) voltage or millivolt systems.