9600 CB & HWG Service Manual
Page 17
1
2
3
4
5
6
7
8
9
RED
RED
CN6
"CONTROL"
1. SWITCH BOILER OFF
2. UNPLUG 9 PIN "CONTROL" PLUG
3. CHECK FOR CONTINUITY AT BACK OF
"CONTROL" PLUG BETWEEN RED WIRES
(BOILER TEMP BELOW 170F)
LIMIT CIRCUIT APPEARS OK -
RECYCLE BOILER A FEW TIMES AFTER
PLUGGING IN "CONTROL" PLUG
CHECK FOR CONTINUITY ACCROSS
OPERATING CONTROL CONTACTS
REPLACE SAFETY LIMIT
REPLACE OPERATING
CONTROL
ALL LIMITS OK.
BOILER SHOULD CYCLE PROPERLY ON
A CALL FOR HEAT OR HOT WATER
PUSH SAFETY LIMIT RESET
BUTTON* BUTTON CLICKS
(0 OHMS ON LOW
OHM SCALE)
CONTINUITY
CONTINUITY
CONTINUITY
NO CONTINUITY
( OHMS)
NO CONTINUITY
TESTING LIMIT CIRCUIT
(YOU MUST COMPLETE PAGE 16 FIRST)
NOTE:
AFTER COMPLETEING LIMIT CIRCUIT TESTING, PLUG IN CONTROL PLUG AND RECYCLE
BOILER A FEW TIMES. IF BOILER A BOILER DOES NOT RECYCLE CONNECT A JUMPER TEMPORARILY
BETWEEN THE RED WIRES. IF BOILER STARTS REMOVE JUMPER AND TEMPORARILY JUMP EACH
SAFETY CONTROL UNTIL THE DEFECTIVE CONTROL IS LOCATED. NEVER LEAVE A SAFETY CONTROL
JUMPED.
* CHECK BOILER PUMP IF SAFETY LIMIT HAS TRIPPED.
CONTINUITY
CHECK FOR
CONTINUITY ACROSS
VENT (EXHAUST) TCO
YES
NO
NO OVERHEAT CONDITION
HAS OCCURRED
CHECK FOR CONTINUITY ACCROSS
SAFETY LIMIT CONTACTS
NO CONTINUITY
REPLACE VENT
(EXHAUST) TCO
NO
CONTINUITY
