15.0
Fault Finding
52
© Baxi Heating UK Limited 2005
Is
the system
full of water ?
Fill system with water and
bleed out all air.
YES
NO
With
water flowing out
of a fully open DHW tap
does the pump
run ?
Unplug the
pump is there
240V at C ?
Is
there 240V at D ?
Replace PCB.
Wiring from terminal
block to PCB faulty.
Pump fault.
Wires from inline
connector to PCB faulty.
Remove blockage.
YES
YES
NO
NO
NO
NO
YES
YES
YES
NO
YES
Unplug
5-way PCB connector.
With water flowing out of a fully
open DHW tap is there
continuity at
E ?
DRY-FIRE
Replace PCB.
Disconnect
primary flow switch
inline connector, with a tap open
is there continuity
across flow
switch ?
Remove
flow switch from boiler.
Is there a physical blockage to the
paddle within the
flow switch ?
Is
there a blockage in
the system ?
Remove blockage.
NO
Replace flow switch.
NO
YES
E
Viewed from
Wire Entry end
C
Pump Plug
(when unplugged)
D
Off
On
Flash
Flash
ON
LED
Lights