52
FAULT FINDING
F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING F
AUL
T FINDING
IMAX XTRA EL
-
Installation & Servicing
68 NO DISPLAY
Supply power to the boiler
no
Is there 230Vac to the boiler at (E)?
yes
yes
Connect the wiring from the terminal block
to the main PCB securely
no
Is the wiring from the boiler terminal block to the main
PCB connected securely?
yes
yes
Connect the cable from the main PCB to
the user interface PCB securely
no
Is the cable from the main PCB to the user interface
PCB connected securely?
yes
yes
yes
Replace cable from main PCB to user
interface PCB
no
Does the cable from the main PCB to the user interface
PCB have continuity and is it un-damaged?
yes
yes
Replace main PCB
yes
Replace the user interface PCB, still no display?
0-10+
0-10-
DHW+
DHW-
OWC+
OWC-
OT+
OT-
PW
M
GND
INT
INT
LOCKOUT
LOCKOUT
BURNER ON
BURNER ON
N
L NO
L NC
N
L
L
N
LIVE OUT
CH CALL
LIVE OUT
DHW/CH2 CALL
HEAT
DEMAND
23
0v
50
Hz
MAINS
IN
230v
50Hz
DHW/
CH2
PUMP/
VALVE
CH/
BOI
LER
PUMP
VOLTS
FREE
CONTACTS
INTER/
LOCK
PUMP
CONTROL
0-10v
INPUT
TANK
SENSOR
OUTSI
DE
SENSOR
OPEN
THERM
switched
live
pump
control
0-10V
0 10
opentherm
master
- +
supply
All Mains Voltages are measured
between the test point and neutral
E
Check for shorts on Pumps/Diverter Valve/
Fan/Spark Generator/Gas Valve and
replace Fuse
no
Is the Fuse on the main PCB OK?
