Quick Start Manual

15.0 Fault Finding
57
© Baxi Heating UK Limited 2005
NO
YES
With water
flowing out of a fully
open DHW tap, does the
DHW LED light ?
Unplug
diverter valve.
With DHW LED on, is
there 240V from
Y to Z ?
NO
DHW Fault
Unplug
5-way connector
from PCB. With water flowing
out of a fully open DHW tap,
is there continuity
across X ?
Unplug
DHW F/S inline
connector. With water flowing
out of a fully open tap, is there
continuity across DHW
flow switch ?
Is DHW flow switch
blocked ?
Replace DHW Flow
Switch.
Unblock DHW Flow
Switch.
Wiring from PCB to Flow
Switch faulty.
Replace PCB.
YES
NO
Unplug
7-way PCB connector.
With DHW LED on, is
there 240V from
B to C ?
Replace PCB.
NO
Wiring from PCB to
Diverter Valve faulty.
YES
Is there 240V from
A to Z ?
YES
Unplug
7-way PCB connector.
With DHW LED on, is
there 240V from
B to D ?
Wiring from PCB to
Diverter Valve faulty.
Diverter Valve faulty. PCB faulty.
NO
NO
YES
YES
NO
YES
YES
NO
Viewed from
Wire Entry end
X
A
Z
Y
Diverter Valve Plug
(when unplugged)
B
C
D