The T8000, T8001 Thermostats provide single-stage,
programmable temperature control for 24 Vac heating-
cooling systems with manual changeover from heat to
cool. Heating cycle rate is selectable at 1, 3, 4, 5, 6, 9, or
12 cph. Cooling cycle rate is fixed at 3 cph. Temperature
indication can be set for °F or °C.
The T8001 Thermostat is powered directly from the
system transformer. The T8000 Thermostat is powered
through the heating/cooling system controls. Batteries are
not required because setpoints are held permanently by
The T8000 and T8001 include a thermostat, wallplate and
owner's guide. A 7 3/8 in. (188 mm) x 5 3/4 in. (146 mm)
decorator cover plate (for covering wall marks) is available
separately. Order Honeywell part no. 209649A (taupe) or
part no. 209649B (white).
If this control is replacing a control that contains
mercury in a sealed tube, do not place your old
control in the trash. Dispose of it properly.
Contact your local waste management authority for
instructions regarding recycling and the proper
disposal of a control.
When Installing this Product...
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazard-
2. Check the ratings given in the instructions and on
the product to make sure the product is suitable for
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Table 1. Description of Thermostats.
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3. Installer must be a trained, experienced service
4. After installation is complete, check out product
operation as provided in these instructions.
Can damage heating/cooling system.
Disconnect power at furnace or main breaker/
Install the thermostat about 5 ft (1.5m) above the floor in
an area with good air circulation at average temperature.
See Fig. 1. Do not install the thermostat where it can be
— drafts or dead spots behind doors and in corners.
— hot or cold air from ducts.
— radiant heat from the sun or appliances.
— concealed pipes and chimneys.
— unheated (uncooled) areas such as an outside wall
behind the thermostat.
Mounting Wallplate to Wall
Level only for appearance. The thermostat
functions normally even when not level.
Mount wallplate and the thermostat with the screws
provided (see Fig. 2) as follows:
1. Place the wallplate at the desired location on the
2. Pull the thermostat wire through the wallplate
3. Fasten the wallplate to the wall using the anchors
and screws provided.
4. After wiring the wallplate, plug the hole with non-
flammable insulation to prevent drafts from affecting
the thermostat; see Wiring section.