CT8602C
Professional Fuel Sa ver Thermostat
Application
This thermostat provides energy saving control for a
24 Vac gas, oil, or electric heating or heating/cooling
system with independently controlled fan. System switch
positions include HEAT-OFF-COOL: fan switch positions
include ON-AUTO.
Power is supplied for the device by three AA alkaline
batteries (included in package). This allows the thermostat
to be compatible with all control applications.
Heat and cool anticipation is fixed; no adjustment is
necessary. Cycle rates are adjustable for heating.
The current rating is 1.6A maximum up to 30 Vac.
Recycling Notice
M3375
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
your old control.
If you have any questions, call Honeywell Inc. at 1-800468-1502.
Installation
WHEN INSTALLING THIS PRODUCT…
1. Read these instructions carefully. Failure to follow
them could damage the product or cause a hazardous
condition.
2. Check the ratings given on the product to make sure
the product is suitable for your application.
3. After installation is complete, check out product
operation as provided in these instructions.
4. Allow thermostat to warm to room temperature
before operating.
CA UTION
Disconnect power supply to prevent electrical
shock or equipment damage.
Do not install the thermostat where it may be affected by:
— drafts or dead spots behind doors, in corners, or under
cabinets.
— hot or cold air from ducts.
— radiant heat from sun or appliances.
— concealed pipes and chimneys.
— unheated (uncooled) areas such as an outside wall,
behind the thermostat.
IF REPLACING AN EXISTING THERMOSTAT
Turn off power to thermostat at furnace or boiler. A two-
transformer system may require turning off two switches or
disconnects. Remove any existing wallplate or subbase
from wall. To avoid miswiring later, label or write down
each wire with the letter or number on the wiring terminal
as the wire is removed.
IF NEW INSTALLATION
Run cable to the hole in the selected wall location, and
pull about 3 in. (76 mm) of wire through the opening.
Color-coded, 18 gauge thermostat cable with at least one
conductor for each wiring terminal is recommended.
MOUNTING WALLPLATE
Remove thermostat from wallplate (Fig. 1).
The wallplate does not require leveling for operation,
but only for appearance. The wallplate mounts directly
onto the wall with the screws included in the package. Use
the wallplate as a template, and with a pencil, mark two
mounting screw positions that best fit the application using
two of the three mounting holes in the wallplate (Fig. 2).
Use 3/16 in. bit to drill holes for anchors. Gently tap
anchors into holes until flush with the wall surface. Thread
wires through the center opening of the wallplate. Then
mount the wallplate using the two screws provided. Gently
tighten screws, level top surface of wallplate, and securely
tighten the screws.
Fig. 1—Removing thermostat from wallplate.
IMPORTANT: Push excess wire back into the hole, and
plug the hole with non hardening caulk, putty or
insulation to prevent drafts from affecting thermostat operation.
LOCATION
Install thermostat and wallplate about 5 ft. (1.5m)
above the floor in an area with good air circulation at
room temperature.
S. M. • Rev. 3-95 • • ©Honeywell Inc. 1995 • Form Number 69-0446—2
M8850
1 69-0446—2
M3375
Fig. 2—Mounting wallplate on wall. Fig. 4—CT8602C heating-only circuit in a
continuous pilot gas system.
WALL
ANCHORS
(2)
WIRES THROUGH
WALL OPENING
USE TWO MOUNTING HOLES THAT
1
BEST FIT APPLICATION.
WALL
WALLPLATE
MOUNTING
HOLES (3)
1
MOUNTING
SCREWS (2)
M2917
WALLPLATE
FACTORYINSTALLED
JUMPER
G
W
FAN RELAY
GAS
1
L2
L1
(HOT)
1
VALVE
24V
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
RCR
Y
M121A
WIRING
All wiring must comply with local electrical codes and
ordinances.
Disconnect power before wiring to prevent electrical
shock or equipment damage.
The shape of the terminal barrier permits insertion of
straight or conventional wraparound wiring connections.
Either method is acceptable.
Refer to Table 1 and Fig. 4 through 8 for wiring guidelines.
NOTE: Keep all wiring restricted to ribbed area surrounding
terminals (Fig. 3) to assure thermostat/wallplate contact.
TABLE 1—TERMINAL CROSS REFERENCE.
Old Thermostat
Terminal Marked Function
G or F Fan G
Y or C Cooling Y
W or H Heating W
RC, V, VC or R Power RC
RH, M, VR, 4 Power R
Fig. 3—Keep wiring restricted to ribbed area
surrounding terminals.
FOR STRAIGHT
INSERTION –
STRIP 5/16 in. [8 mm]
FRONT VIEW OF
TERMINAL AREA
WIRING TO BE BELOW
THIS SURFACE
CROSS-SECTIONAL VIEW OF
TERMINAL AREA
New Thermostat
Terminal Marked
FOR WRAPAROUND –
STRIP 7/16 in. [11 mm]
RESTRICT
WIRING TO
THIS AREA
TOP SURFACE
OF SUBBASE
M2927
Fig. 5—CT8602C heating-only circuit in an oil
system.
WALLPLATE
FACTORYINSTALLED
JUMPER
G
W
L1
HOT
)
(
1
L2
POWER SUPPLY. PROVIDE DISCONNECT MEANS
1
AND OVERLOAD PROTECTION AS REQUIRED.
TT
OIL PRIMARY
RCR
Y
M122
Fig. 6—CT8602C heating/cooling circuit in a
single transformer system with gas heat and
electric cooling or electric heat and electric
cooling, RC and R terminals.
WALLPLATE
FACTORYINSTALLED
JUMPER
G
W
FAN RELAY
2
HEATING
PRIMARY
CONTROL
24V
POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
PRIMARY CONTROL SUCH AS GAS VALVE OR
ELECTRONIC IGNITION MODULE.
L1
HOT
(
L2
1
)
1
2
RCR
COOLING
CONTACTOR
Y
M119
69-0446—2 2