Rev. B 4-5-02
P/N 472089
11
PRESS
PRESS
HEATER FIRING - NORMAL OPERATION
NOTE: SERVICE LED LIT FLAGS PROBLEM, TFUSE LED OFF SHOWS PROBLEM
PRESS
PRESS
THERMOSTAT CALLING FOR HEAT - BLOWN THERMAL FUSE BLOCKS FIRING
FRONT PANEL LEDS
HEAT
PRESS
AUX
SERVICE
TRANSFORMER
THERM
POWER
INCOMING
LINE VOLTAGE
FRONT PANEL LEDS
PRESS
HEAT
AUX
THERMOSTAT
PWR
CIRCUIT
BREAKER
TSTAT
RELAY
RMT
REMOTE
TRANSFORMER
THERM
INCOMING
LINE VOLTAGE
THERMOSTAT
PWR
BREAKER
CIRCUIT
TSTAT
RELAY
RMT
REMOTE
THERMOSTAT CIRCUIT BOARD
NO MV
CLOSE IF
IGNITION MODULE
SRVE
HI TEMP
LIMIT SWITCHES
HI TEMP
TFUSE
MV
IND
TFUSE
GND
THERMOSTAT CIRCUIT BOARD
GAS VALVE
HEAT
VAL
MV
MV
IGNITION MODULE
SRVE
CLOSE IF
NO MV
HI TEMP
LIMIT SWITCHES
HI TEMP
TFUSE
MV
IND
TFUSE
GND
GAS VALVE
HEAT
VAL
MV
MV
POWER
SERVICE
IS IN THERMAL FUSE CIRCUIT
SYMBOL TABLE
LED LIT
LED OFF
SWITCH OR DEVICE
OPEN CIRCUIT
(BLOCK CURRENT)
SWITCH OR DEVICE
CLOSED CIRCUIT
(PASS CURRENT)
TROUBLESHOOTING (CONTROLS) - Continued
Installation (Operating Controls, cont’d.)
