© Baxi Heating UK Ltd 2008
40
Fig. 48
Air Pre
ss
ure
S
witch
S
tuck Fault
Refer to the boiler wiring diagram
Lockout Burner Mains
Yes
No
After 15
seconds,
does the fan run
Switch the boiler on
Yes
No
Unplug
the 12 way
connector from PCB.
Is there continuity
between the
2 orange
wires
No
Refit the
12 way
connector to PCB.
Unplug one APS lead
Switch boiler
on. Does fan
run ?
Replace PCB
Yes
Replace fan
Yes
Unplug the
APS leads
Is there continuity
across the
the APS
APS stuck in the
On position. Replace
Short circuit on the
wiring - rectify
No
Yes
Rectify fault
Switch off
Unplug the
12 way connector and
both APS leads
Is there continuity
between the
2 orange
wires
Open circuit on the
APS wiring - rectify
Yes
Check the
tubes from venturi
to the APS. Check for
blockages in condensate
system, flue and
heat exch.
APS stuck in Off position
Replace
No
No
flashing
off
off
Yes
Is
there
230 V
at the
fan ?
Open circuit on
the wiring. Rectify
No