The T8000C Thermostat provides single-stage, program-
mable 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 T8000C Thermostat is powered through the heating/
cooling system controls. Batteries are not required
because setpoints are held permanently by non-volatile
The T8000C model includes 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.
®U.S. Registered Trademark
Copyright © 2002 Honeywell •
Table 1. Description of T8000C Thermostats.
• All Rights Reserved
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
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/fuse
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.