Main 12 HE A - Page 54

17.0 Fault Finding
54
© Baxi Heating UK Ltd 2014
DRY-FIRE
NO
Fill system with water and
bleed out all air.
Replace PCB.
YES
NO
YES
NO
Is the
system full of water ?
Is the
pump running ?
Unplug
5-way PCB
connector. Is there continuity
between H (run pump from
switched live) ?
Disconnect
Flow Switch Inline
connector. With pump running is
there continuity across flow
switch ?
Remove Blockage.
NO
YES
NO
YES
Turn
mains off & on. After 5 sec, is
there 240V
at E?
Pump or Pump Wiring
fault.
Is there a
blockage in the system ?
NO
YES
YES
E
Optional
Pump
Live
N
L
F
N
L
Turn
mains off, unplug
7-way connector to PCB.
Is there continuity between
F and G ?
Wiring from terminal
block to PCB faulty.
NO
YES
Replace PCB.
Wires from inline
connector to PCB faulty.
Remove
flow switch from boiler.
Is there a physical blockage to
the paddle within the
flow switch ?
Replace Flow Switch.
Remove Blockage.
YES
NO
G
Viewed from
Wire Entry end
H
7-way Connector
Lights
On Flash Flash
ON
Optional
Pump
Live
Swop Flow & Return.
Are
Flow & Return reversed ?
YES
NO