1 of 3
Photo 1: Remove the old thermostat
Turn off power to the heating
and cooling systems at
the main panel. Mark the
wires with a tab (or tape) and the
letter that represents the terminal
and unscrew them. Remove and
discard the old thermostat.
2 of 3
Photo 2: Install the mounting plate
plate in position
plate to the
3 of 3
Photo 3: Hook up the wires
wiring to the
on the new thermostat
the letter labels
(strip the wires
back if necessary).
up to the same
terminals on the
Snap the thermostat
to the mounting plate.
You can reduce your
home's heating and
cooling costs by about
15 percent with a programmable
thermostat. It automatically keeps
the temperature at a comfortable
level when you're home, but
switches to an energy-saving level
when you're away or asleep.
Programmable thermostats are
available from home centers and
hardware stores. The higher-priced models provide
more programming options.
Programmable thermostats will
work with most gas or oil furnaces
and central air conditioners.
However, heat pumps, electric
baseboards, and a few other systems
require special features. Read
the package to make sure the programmable
thermostat you buy is
compatible with your heating and
cooling system. If you're unsure,
call your local utility or a heating
and cooling contractor.
Remove the old thermostat as
shown in Photo 1. If your old thermostat
contains mercury, you'll see
a small glass tube with a shiny silver
ball inside. Mercury is toxic. Take
this type of thermostat to a hazardous
waste disposal site.
There will be anywhere from two
to five wires hooked up to the old
thermostat. Label the thermostat
wiring with marking tabs using the
letters on the old screw terminals as
reference. If your new thermostat
doesn't come with marking tabs,
use masking tape.
Clip a clothespin to the cable so it
doesn't slide down inside the wall
cavity, and mount the new wall
plate (Photo 2). If the thermostat
has back-up batteries, insert them
before wiring the new thermostat
The thermostat may need to be
configured to your heating system.
It may also come preprogrammed,
but to maximize savings, set it up
according to your schedule. Consult
the instructions that come with the
thermostat for system adjustments
and programming. You won't save
energy if the thermostat isn't programmed