Replacing
A Mercury Thermostat With A Programmable Digital
By Lou Granata
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| Before |
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| After |
There are
many digital thermostats on the market today. These can be used
to replace most conventional low voltage and millivolt thermostats.
One of the advantages to a programmable thermostat is the ability
to save energy and money on your utility bills. According to
the the U.S. Department of Energy, a programmable thermostat
can reduce heating costs by up to 35% and cooling costs by up
to 25%. Your savings will largely depend on the length of your
energy saving program periods and the temperatures set. Programmable
thermostats automatically change the thermostat's set temperature
between comfort levels and energy saving levels at specified
times, according to the programs you set up. Generally, to save
energy, you would set up four program periods for each day —
two comfort programs (day/night) and two energy saving programs
(work/sleep), plus different settings for weekends. Read all
instructions before installing. You will need batteries, so
purchase at the same time you purchase your thermostat.
Replacing
Your Thermostat
You must turn off the electricity to the appliance before installing.
Do not turn the appliance back on until the installation is
completed. Get your house toasty if it is cold outside before
turning off the heater.
Remove the
old unit from the wall (figure 1). Note the letters printed
near the terminals of the old thermostat that will correspond
to the new unit. Attach labels to each wire for identification
(figure 2). Do not let the bare wires touch each other
or parts on thermostat.
Hold the
base against the wall, with the wires coming through so it is
convenient for rewiring. Position the base for best appearance
(to hide any marks from old thermostat) and mark where the mounting
screws will be located (figure 3). Digital thermostats
do not need to be level to work but the unit will look better
if leveled.
Drill holes
where the mounting screws will go (figure 4). If you
do not hit a stud use the drywall anchors that came with the
unit. Attach the base to the wall. Attach wires to the terminals
that are outlined in the wiring diagram that came with the unit.
Mount the main unit to the base and turn on the appliance. Some
units have an override button, use it to test the thermostat.
If you run into problems call your supplier or the manufacture
of your unit.
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 |
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| Figure
1 |
Figure
2 |
Figure
3 |
Figure
4 |
| Tools
& Materials |
Screwdriver, drill with 3/16"
bit, and a level. |
| Where
to Purchase |
A Boy Electric
& Plumbing
(503) 225-9009
(800) 691-7895 for nearest location |
| Permits
& Codes? |
Log onto:
www.opdr.ci.portland.or.us |
| Average
Cost |
Will vary with
unit you buy |
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