Installation Instructions for the Trained Service Technician.
1. Disconnect power supply to prevent electri-
The T87F Universal Thermostat provides tempera-
cal shock or equipment damage.
ture control for 24 to 30 Vac residential heating, cooling
2. To prevent interference with the thermostat
or heating-cooling systems. For heating systems, the
linkage, keep wire length to a minimum and
T87F mounts on the wallplate provided. For cooling
run wires as close as possible to the subbase.
only, or heating-cooling, order the 137421A (198170A
3. Do not overtighten thermostat captive mount-
if textured designer model) Heating-Cooling Wallplate
ing screws because damage to subbase threads
with remote switching, or the Q539 Subbase, which
provides switching at the thermostat location.
4. Do not short across coil terminals on relay.
The spdt switch makes one set of contacts on a tem-
This can burn out the thermostat heat antici-
perature fall to operate the heating system. The other set
of contacts make on a temperature rise to operate the
cooling system when the T87F is used to control cool-
IMPORTANT: An incorrectly leveled thermostat will
cause the temperature control to deviate from set
Heat anticipation is adjustable, 0.1 to 1.2A.
Install the thermostat about 5 ft [1.5m] above the
floor in an area with good air circulation at average
This control contains mercury in a sealed tube. Do not
place control in the trash at the end of its useful life.
Do not install the thermostat where it may be affected
If this control is replacing a control that contains
mercury in a sealed tube, do not place your old control in
— drafts, or dead spots behind doors and in corners.
— hot or cold air from ducts.
Contact your local waste management authority for
— radiant heat from sun or appliances.
instructions regarding recycling and the proper disposal
— concealed pipes and chimneys.
of this control, or of an old control containing mercury in
— unheated (uncooled) areas such as an outside wall
a sealed tube.
behind the thermostat.
If you have questions, call Honeywell Inc. at 1-
This thermostat is a precision instrument and was
carefully adjusted at the factory. Handle it carefully.
MOUNTING WALLPLATE OR SUBBASE (Fig. 2)
Installation and Setting
1. Use a spirit level to accurately level the wallplate
WHEN INSTALLING THIS PRODUCT...
or subbase as in Fig. 1. Inaccurate leveling may
1. Read these instructions carefully. Failure to fol-
cause thermostat control deviation.
low them could cause a hazardous condition.
2. When using the T87F with a Q539 Subbase, follow
2. Check the ratings given in the instructions and on
the mounting and wiring instructions included with
the product to make sure the product is suitable for your
3. Installer must be a trained, experienced service
1. Place the wallplate on the wall at the desired loca-
tion. Pull the thermostat cable through the entrance hole.
4. After installation is complete, check out product
2. Fasten wallplate. Do not tighten the screws.
operation as provided in these instructions.
3. Level according to Fig. 1 then tighten screws.
4. After wiring wallplate, plug hole to prevent drafts
from affecting thermostat.
NOTE: To mount T87 Thermostat on an outlet box,
order 129044A Adapter Ring Assembly.
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