Potterton Promax FSB 30 HE Installation & Service Instructions Manual page 53

IGNITION LOCKOUT
Is there
gas at gas valve inlet ?
YES
Reset Lockout.
Is there gas flow
(check at meter) ?
YES
Is
there at least
18mbar dynamic at gas valve
inlet ?
YES
Is
Condensate Trap
blocked or water on
terminals ?
NO
Is
Condensate Pump
reservoir full ?
NO
Is
spark or flame detection
probe damaged ?
NO
Is
spark gap between 3 and
4mm ?
YES
Is
wiring from PCB
to spark probe & flame
detection probe OK ?
NO
Rectify wiring.
© Baxi Heating UK Limited 2010
Lights
On Off On
NO
Check isolation valve and
gas supply.
NO
Remove Gas Valve & check
NO
inlet filter for blockage.
Otherwise incorrect gas supply
to boiler.
YES
Clear blockage and dry
sensors.
YES
Check and if necessary
change over level switch
(see Section 13.5)
YES
Replace spark or flame
detection probe and
gaskets.
NO
Set spark gap to 3.5mm.
YES
Is the
burner blocked or
damaged ?
YES
Clean burner or replace as
necessary.
17.0 Fault Finding
I
J
Remove
5-way connector
from gas valve. Is there 240
Vdc between I & J
during ignition ?
NO
Remove
the larger of the
two 6-way PCB connectors.
Is there continuity from I to L
& from J to K ?
YES
Replace PCB.
6-way Connector
NO
Replace PCB.
Gas Valve 5-way
Connector Plug
YES
Replace Gas Valve.
NO
Lead from PCB to Gas
Valve faulty.
K
L
53