FAULT FINDING
Continued from page
52 of fault finding
no
With the boiler and heating circuit warm does the burner pressure reduce if the heating temperature setting is reduced to minimum?
yes
no
When a DHW tap is
opened and the DHW temperature is set to maximum, does the water become hot?
Is there between 0V dc
and 16V dc at the connections on the modulating coil? (0=min, 16=max)
yes
Is the burner pressure within min and max value* with the boiler running?
yes
Repair faulty gas
valve
Is the boiler mode
setting correct?
(Refer to frame 62)
yes
no
no
Adjust burner pressure. Refer to frame 35.
no
Follow the instruction “Boiler mode setting” (Refer to frame 62)
Is the continuity of the
modulator harness
O.K?
yes
Repair faulty PCB
no
Repair or replace
faulty wiring
FAULT FINDING
yes
Is the red LED
illuminated on DHW
flow sensor?
yes
no
Is there 230V
ac between
Blue and
Black at the
yes
Remove the |
| |
motor |
| |
assembly, with |
| |
230V at the |
| |
connections is |
| |
the spindle fully | no | |
retracted? Refer | ||
| ||
to frame 76. |
|
yes
Replace
faulty valve
body
assembly
no
Is the
continuity of
the
valve harness O.K?
yes
Repair faulty
PCB
Replace
faulty motor
assembly
no
Is there 5V dc between
Red and Blue on
connecting harness?
yes |
no |
Repair or |
replace |
faulty |
wiring |
no
Replace the
sensor. Is
red LED
illuminated?
yes
Faulty sensor now replaced
no
Is the harness continuity O.K?
yes
Repair faulty PCB
no
Dismantle the DHW detector valve and clean. Refer to frame 66.
Reassemble.
Does the DHW water become hot?
yes
Repair or
replace
faulty wiring
Repair or
replace
faulty DHW
detector
valve
Continued on page 58 of fault finding
* see Table 2 at page 4 for the correct value
mini HE | 53 |
