FAULT FINDING
50
Mini
--- Installation & Servicing
Continued from
page 48 of fault
finding. Is there at
least one of the
LEDs flashing?
Is LED 1 flashing with
LED 2 on ?
When the pump
runs does the
spindle of the water
flow detector
extend to operate
the micro switch?
Refer to frame 57.
Replace faulty
diaphragm and clean
housing of debris, if any.
refer to frame 58.
Continued on page
51 of fault finding
no
yes
no
no
no
no
no
no
no
no
no
yes
yes
yes
yes
yes
yes
yes
yes
Check resistance of
DHW temperature
probe. Is it between
12 k
Ω
and 1.5 k
Ω
?
Check resistance of
CH temperature
probe. Is it between
12 k
Ω
and 1.5 k
Ω
?
Are LED2 and LED 3
flashing?
Replace faulty
thermistor
Are LED2 flashing
and LED 3 on?
Replace faulty
thermistor
Repair or replace
faulty wiring
Repair or replace
faulty wiring
Remove the pump
nut. Does the pump
rotate freely when
turned)
Replace faulty pump
Re---pressurise
system and vent
Is the heating circuit
pressurised to at least
1 bar and fully vented
of air?
Is the continuity of
the micro switch
harness O.K?
Replace faulty micro
switch
Is there continuity
between C and NO
contacts on micro
switch when the
switch is operated?
Repair or replace
faulty wiring
Replace faulty PCB
yes
FA
UL
T
F
IND
ING