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conditioning equipment to return the building from the
energy saving temperature to the comfort temperature.
The thermostat starts the recovery period early so the
building will be at the comfort setting by the time the
owner has chosen.
Setback
Reducing the temperature in the building for a set period
in heating for energy savings. The lower temperature is the
energy savings temperature.
Setup
Raising the temperature in the building for a set period in
cooling for energy savings. The higher temperature is the
energy savings temperature.
Setpoint
The thermostat temperature setting the owner selects. The
thermostat turns the heating or cooling equipment on and
off to maintain this temperature at the thermostat location
until another temperature setting (setpoint) goes into ef-
fect.
SYSTEM light (yellow)
This light glows whenever the thermostat is calling for
heating or cooling (located on thermostat).
Time period
One of four program periods: MORNING, MIDDAY,
EVENING, and NIGHT; available with the Chrono-
therm III™ Thermostat. One period begins when the
previous program period ends.
MORNING—The time period when the owner brings
the building to a comfortable temperature to begin the
day. This is the only period that must contain a time and
temperature for every day.
MIDDAY—The time period when the owner can set
back (heating) or set up (cooling) the temperature for
daytime energy savings if the building is unoccupied.
EVENING—The time period when the owner wants
the building at a comfortable temperature for evening
activities after daytime energy savings.
NIGHT—The time period when the owner can set
back (heating ) or set up (cooling) the temperature for
energy savings because family members are asleep or
the building is unoccupied. Often a NIGHT energy
savings temperature is set only for the heating season so
family members can sleep cool in summer.

Glossary

AUX. HT. light (green)
This light glows whenever the thermostat is calling for
operation of the backup heater. Backup (auxiliary) heat is
more expensive to operate than the heat pump, and typi-
cally is used only when the heat pump is unable to handle
the load (located on subbase).
CHECK light (yellow)
Consult heat pump literature to determine its meaning
(located on subbase).
Comfort temperature
The temperature desired when active and occupying the
building.
EM. HT. light (red)
This light glows whenever the thermostat system switch is
in the EM. HT. position (located on subbase). On some
systems, it may also indicate the need to switch to EM. HT.
because of a heat pump problem.
Energy-saving temperature
The lower (heating) or higher (cooling) temperature that
allows savings on heating and cooling costs when asleep
or away. Also called the setback (heating) or setup (cool-
ing) temperature.
Preprogrammed schedule
This is the schedule programmed into the thermostat at the
factory. It sets a night program that provides energy
savings if owner does not set his/her own program, or if
personal program is lost for any reason. The program,
which is the same for all days of the week, is:
Start Temperature
Period Time Heating Cooling
MORNING 6:00 AM 70° F78° F
MIDDAY - - - - - -No program - - - - - - - - - -
EVENING - - - - - -No program - - - - - - - - - -
NIGHT 10:00 PM 60° F78° F
Program
The times and temperatures the owner sets to define the
comfort and energy saving periods for each day’s sched-
ule.
Recovery
The time when the thermostat operates the heating or air
T8611M
GLOSSARY