Service manual
Figure 13
WIRING DIAGRAM
120 V 60HZ LESS THAN 5 AMP.
IF ANY OF THE ORIGINAL WIRE AS SUPPLIED
WITH THE APPLIANCE MUST BE REPLACED.
IT MUST BE REPLACED WITH 18 GA
STRANDED 105˚C. WIRE OR ITS EQUIVALENT.
WIRING DIAGRAM
W (NEUTRAL)
VAC
VAC24
120
W O
1
2
B
BR YY
Y
DISCONNECT
POTENTIOMETER
UPPER
RELAY
LOWER
RR
B
B
B
B
24V (GND)
DAMPER
3 4
21
BK
BK
W R Y
R
W
Y
G
BK
R
=
=
=
GREEN
BLACK
RED
W
Y
O
=
=
=
WHITE
YELLOW
ORANGE
B = BLUE
BK (HOT)
G (GROUND)
W
BK
IGNITION CONTROL
HONEYWELL S8600C
N O
MV
1 2 3 4 5 6 7 8 9
MV/PV
PV
24V
24V
G
G
R
B
SENSE
SPARK
GAS VALVE
TRANSFORMER
HNYWL
VR8304
PV
PV/MV
MV
(GND)
(BURNER)
TH-V
(GND)
(OPT)
WARNING
OPERATION
In the standby condition (thermostat satisfied) relay contacts R1 are closed and the motor (DM) is energized, which drives the damper
vane closed. This opens the end switch '(ES) via a cam on the drive rod. When the damper is fully closed, the safety switch (N/C) contacts
(SS I) are closed by the other drive rod cover. The torsion spring is wound up. Closure of the thermostat (TH) energizes the relay coil
(R) which opens the R1 contacts. The motor is de-energized and the spring drives the damper vane to the open position, the cam opens
the safety switch contacts (SS2) and closes (SS I), and the end switch contacts (ES). Closing of the end switch energizes the control
module. When the thermostat is satisfied, it de-energizes the control module and the relay coil (R). De-energizing the relay closes the R1
contacts which energizes the motor, driving the damper vane to the closed position.
In the event of an end switch malfunction, where the contacts remain closed, the safety circuit detects this condition and disables the
damper in the open position. This is accomplished when the thermostat closes on the next call for heat, by a direct short through
contacts, (SS2), (ES), the fuse, and the thermostat. The short causes the fuse to blow, opening the motor circuit, which causes the damper
to spring open and remain open. This will disable the damper in the open position and allow the appliance to remain operational.
TO AVOID POSSIBLE INJURY. FIRE AND EXPLOSION, READ THESE PRECAUTIONS BEFORE ATTEMPTING TO LIGHT OR
RELIGHT THE PILOT. Check the rating plate near the gas control thermostat for correct gas. DO NOT USE THIS WATER HEATER
WITH ANY GAS OTHER THAN THE ONE LISTED ON THE RATING PLATE (Figure 5). Failure to use the correct gas can cause
problems which result in DEATH, SERIOUS BODILY INJURY, OR PROPERTY DAMAGE. If you have any questions or doubts consult
your gas supplier or gas company.
Figure 14
DAMPER OPERATION SEQUENCE
SERVICE SWITCH
LEGEND
DM Damper Motor
F Fuse
TH Thermostat
ES Endswitch
CM Control Module
R Relay Coil
R1 N/C Relay Contact
R2 N/O Relay Contact
SS1 N/C Safety Switch Contact
SS2 N/O Safety Switch Contact
VOLTAGE 24 AC
L2
2
4
ES
R
SS2
3
24V 24V
GRN
CM
SS1
TH
M
1
DM F
R1
L1
20
19