Heating, Cooling, and Heating/Cooling
Thermostat, Wallplate and Subbase—
Check thermostat and subbase (if used) suitability for
the heating, cooling, or heating/cooling system. Refer to
Table 1.
Assemble tools required: flat-bladed screwdriver, hand
or power drill with 3/16 in. drill bit, wire cutter/stripper or
sharp knife, bubble level or plumb bob and line.
TABLE 1— SYSTEM COMPATIBILITY FOR NON-BATTERY POWERED THERMOSTATS.
Type of Heating System
to be Controlled
Electric (Line Voltage)—typical
baseboard and radiant
Gas—Direct Spark Ignition (DSI),
Intermittent Pilot (IP), and Standing Pilot
(SP)
Hot Water Zone
Oil
Vent Damper
Warm Air Zone
a If thermostat is not compatible with the system being controlled, the system will not operate. No hazard exists. The thermostat
will not be damaged unless it is used to directly control a line voltage system. For proper system operation, a Honeywell R841
or R8239D1015 Isolating Relay must be added to the thermostat control circuit.
b Consult manufacturer for installation requirements.
Installation Instructions
Preparation
cooling system at the main fuse panel. Most buildings have
a separate switch box or circuit breaker for disconnecting
power to the heating and cooling (if applicable) equipment.
or heating/cooling systems when thermostat is powered by
batteries. If thermostat is not powered by batteries, refer to
Table 1 for thermostat and system compatibility informa
tion.
• The R8239D1015 Isolating Relay or R841 Silent Switching Center
must be installed in the thermostat control circuit.a
• Compatible. If not using battery backup, assure that 24 V control
transformer common is accessible for connection to thermostat
cable conductor and power to the transformer is not regularly
interrupted by high temperature or limit operation.
• Honeywell 2-wire valves are compatible.
• Some non-Honeywell 2-wire valves require an R8239D1015
Isolating Relay in the thermostat control circuit.a
• Some 3-wire valves require an R8239A1052 Isolating Relay in the
thermostat control circuit.a, b
• If not using battery backup, assure that the 24V control
transformer common is accessible for connection to thermostat
cable conductor and power to the transformer is not regularly
interrupted by high temperature, purge cycle, or limit operation.
• Honeywell damper motors are compatible.
• Some non-Honeywell damper motors require an R8239D1015
Isolating Relay in the thermostat control circuit. a Check control
amperage requirement.
• Most are compatible.
D. F. • Rev. 11-94 • ©Honeywell Inc. 1994 •
Honeywell
T8090A/Q682B
Assure power is off to the heating, cooling, or heating/
This thermostat is compatible with all heating, cooling,
Conditions/Compatibility
Form Number 69-0627B— 1
V2