45
BOXER
combination boiler -
Installation and Servicing
FAULT FINDING
F
A
U
L
T FINDING F
A
U
L
T FINDING F
A
U
L
T FINDING F
A
U
L
T FINDING F
A
U
L
T FINDING
72 FAULT FINDING
YES
NO
IS THERE 230 Vac AT THE BOTTOM
CONNECTIONS OF THE OFF/ON SWITCH
IS THE POWER LED
ILLUMINATED
RECTIFY EXTERNAL FAULT
NO
YES
REPLACE FAULTY SWITCH
IS THERE 230 Vac AT CONNECTOR Y2 ACROSS
PINS L1 AND N
RECTIFY WIRING FAULT OR
REPLACE
NO
REPLACE FAULTY FUSE
NO
YES
IS THE CONTINUITY OF FUSE ON THE PCB
OK
REPLACE FAULTY PCB
NO
YES
IS THERE 14 Vdc BETWEEN PIN 3 AT
CONNECTOR TA AND J5
IS THE CH LED ILLUMINATED
ENSURE ALL THE CONTROLS ARE
CALLING FOR HEAT
NO
ARE THE SELECTOR SWITCH, PROGRAMMER
AND ROOM STAT ALL CALLING FOR HEAT
NO
REPAIR OR REPLACE FAULTY
WIRING OR THERMISTOR
YES
TOP UP THE SYSTEM PRESSURE VIA
THE FILLING DEVICE TO AT LEAST 1 bar
YES
YES
ENSURE THE ROOM THERMOSTAT AND
PROGRAMMER ARE CALLING FOR HEAT AND
THE SELECTOR SWITCH IS SET TO HEATING.
ENSURE ALL SERVICES ARE ON AND NO DHW
TAPS ARE OPEN
BEFORE REPLACING THE
PROGRAMMER CHECK THE
ON AND OFF TIMES ARE SET
CORRECTLY
IS THE CONTINUITY OF THE SWITCH IN THE
ON POSITION OK
NO
YES
NO
DISCONNECT PLUG A5 IS THE RESISTANCE
ACROSS PIN 1 AND PIN 2 BETWEEN 0.5kohm TO
50kohm
NO
YES
CHECK THE SYSTEM PRESSURE GAUGE.
DOES IT SHOW A SYSTEM PRESSURE OF AT
LEAST 1bar
NO
CHECK THE PROGRAMMER: IS THERE 3 Vdc
AT THE PCB CONNECTOR A9 ACROSS PINS 2
AND 3
YES
YES
YES