Baxi System 100 HE Plus Installation & Servicing Instructions Manual page 45

DRY-FIRE
Is the
system full of water ?
YES
Is the
pump running ?
YES
Unplug
5-way PCB
connector. Is there continuity
between H (run pump from
switched live) ?
NO
Disconnect
Flow Switch Inline
connector. With pump running is
there continuity across flow
switch ?
NO
Remove
flow switch from boiler.
Is there a physical blockage to the
paddle within the
flow switch ?
YES
Replace Blockage.
Lights
ON
NO
Fill system with water and
bleed out all air.
NO
Is the
pump run off the
switched live?
YES
Pump or Pump Wiring
fault.
YES
Replace PCB.
YES
Wires from inline
connector to PCB faulty.
NO
Is there a
blockage in the system ?
YES
Replace Blockage.
15.0
On
Flash
Flash
N
L
Turn
NO
mains off & on. After 5 sec, is
there 240V
at E?
YES
Pump or Pump Wiring
fault.
Viewed from
Wire Entry end
NO
Replace Flow Switch.
Fault Finding
E
Optional
Pump
Live
YES
NO
7-way connector to PCB.
Is there continuity between
NO
Wiring from terminal
block to PCB faulty.
H
7-way Connector
Replace PCB.
Turn
mains off, unplug
F and G ?
G
F
Optional
N
L
Pump
Live
45