radiant heat from the sun, fireplaces, or appliances.
concealed pipes and chimneys.
unheated (uncooled) areas behind the thermostat,
such as an outside wall.
The T882D two-wire, mercury switch thermostat pro-
vides low voltage control of heating systems and features
an adjustable heat anticipator. Some models include a
positive OFF switch and temperature range stops.
The TS822A two-wire, mercury switch thermostat pro-
vides millivoltage control of heating systems and features
a positive OFF switch.
MOUNTING AND WIRING
Disconnect power supply before beginning installation
to prevent electrical shock or equipment damage.
All wiring must comply with local codes and ordinances.
T822D and TS822A Thermostats are designed to be
mounted on a wall or on a vertical outlet box. In a 250 or
00 mV application, use No. 14 wire if possible and make
the run as short as possible; remember this when select-
ing a location. For maximum wire lengths in a 750 mV
application, see Table 1.
This control contains mercury in a sealed tube. Do not
place control in the trash at the end of its useful life.
If this control is replacing a control that contains mercury
in a sealed tube, do not place your old control in the trash.
Contact your local waste management authority for
instructions regarding recycling and the proper disposal of
this control, or of an old control containing mercury in a
TABLE 1—WIRE LENGTH.
WHEN INSTALLING THIS PRODUCT…
. Read these instructions carefully. Failure to fol-
low them could damage the product or cause a hazardous
. In replacement applications, check the existing ther-
mostat wires for cracked or frayed insulation. Replace any
wires in poor condition. If the wire is plastered into the
wall, make a hole next to the wires and loosen the wires so
they can be pushed back into the wall later.
. Check the ratings given in the Instructions and on
the product to make sure the product is suitable for your
. In new installations, run wiring (if necessary) to the
. Connect the wires to the terminals on the back of the
. Installer must be a trained, experienced service
thermostat. See Figs. 1 through 4 for internal schematic and
typical hookup diagrams.
. After installation is complete, check out product
operation as provided in these Instructions.
4. Remove thermostat cover by pulling outward on
bottom edge of cover until it snaps free of the thermostat
base. Carefully remove and discard the foam plastic ship-
ping insert. This insert protects the switch and bimetal
assembly during shipping.
Disconnect power supply before beginning in-
stallation to prevent electrical shock or equip-
5. Set the adjustable heat anticipator indicator (T822D
only) to match the current draw of the primary heating
control (see Heat Anticipator Setting).
. Push excess wire back through the hole and plug any
opening with insulation to prevent drafts that may affect
Locate the thermostat about 5 ft [1.5 m] above the floor
on an inside wall in an area with good air circulation at
7. Loosely fasten the thermostat to the wall or
outlet box with a screw through the top mounting hole.
Adjust the thermostat so it is approximately level and
start the second screw through the bottom mounting
hole. Do not tighten.
Do not mount the thermostat where it can be affected by:
drafts or dead spots behind doors or in corners.
hot or cold air from ducts.
J. H. • Rev. 2-93 •
• ©Honeywell Inc. 1993 • Form Number 69-0509—2