Thermo Pride CHX3-75N Installation And Operation Manual page 56

All installations and services must be performed by qualified service personnel.
THE SYSTEM IS STARTED BY SETTING THE THERMOSTAT TO CALL FOR
HEAT. THE FOLLOWING SHOULD HELP ESTABLISH THE TYPE OF
MALFUNCTION OR DEVIATION FROM THE NORMAL OPERATION.
NOTE: REFER TO PAGE 48 FOR DEFINITION OF DIAGNOSTIC LEDS.
TO USE THIS DIAGRAM, YOU JUST NEED TO FOLLOW THE INSTRUCTIONS IN THE BOXES.
(MAKE CERTAIN ROOM TEMPERATURE IS BELOW THERMOSTAT SETTING)
IS THE INDUCER
BLOWER OPERATING?
YES
TROUBLESHOOTING GUIDE
SET THERMOSTAT TO CALL FOR HEAT
IS THERE 120 VOLTS
ACROSS "L1" AND
NO
"NEUTRAL" AT THE
50V51-843 CONTROL
MODULE?
IS THERE 24 VOLTS
ACROSS "TH" & "TR"
AT THE INTEGRATED
CONTROL MODEL
50V51-843?
IS THERE 24V
ACROSS R AND B/C
IS THERE 24 VOLTS
ACROSS "R" AND "W1"?
IS THERE LINE VOLTAGE
ACROSS INDUCER POWER
TERMINALS "IND HI" TO
"IND N" OR "IND LO" TO
"IND N" AT THE 50V51-843
CONTROL?
CHECK WIRING TO INDUCER
AND IF OK, REPLACE
INDUCER ASSEMBLY.
NO
YES
NO
YES
NO
YES
YES
NO
NO
YES
50
CHECK INPUT POWER,
DOOR INTERLOCK,
SERVICE SWITCH
AND FUSES
CHECK 115 VOLT
CONNECTIONS. IF OK,
REPLACE TRANSFORMER
CHECK FUSE ON
W/R 50V51-843
CHECK WIRING TO
THERMOSTAT. IF OK,
REPLACE THERMOSTAT.
REPLACE THE
50V51-843 CONTROL.