Removing Your Old Thermostat; Turn Off Power; Check That Your System Is Off; Remove Your Existing Thermostat From The Wall Plate - Honeywell T9 Installation Manual

Removing your old thermostat

1

Turn off power

To protect your equipment, turn off
the power at the breaker box or switch
that controls you heating and cooling
equipment.
Note: The thermostat off switch
will not turn off the power to the
equipment.
2

Check that your system is off

Change the temperature on your old
thermostat so that your system starts
heating or cooling.
If you don't hear or feel the system turn
on within 5 minutes, the power is off.
Note: If you have a digital thermostat that
has a blank display, skip this step.
3 Remove your existing thermostat from
the wall plate
On most thermostats, you can take off
the thermostat by grasping and gently
pulling. Some thermostats may have
screws, buttons, or clasps.
Do not remove any wires from your
thermostat at this time!
You will need: Screwdriver, needle-nose pliers
Breaker box
75
4
ON
OFF
OR
OFF
Switch