Hamworthy Sherborne Series Installation, Commissioning And Service Manual page 37

Figure 12.2. Fault Finding Procedures.
Continued from
Fig 12.1
Does the HSI probe glow?
Yes
Does the burner ignite?
Yes
Is flame sensed by the
ignition controller?
(Fascia boiler run indicator
illuminated)
Yes
Continued
Ref. Fig 12.3
HAMWORTHY HEATING LTD
Does the fan stop (after
No
the post purge) when on/off
switch set to off position?
Yes
Does the fan speed drop
to the ignition speed after
the 20sec pre-purge?
Yes
Is there power to the
ignition controller?
Yes
Is there an HSI signal from
the ignition controller?
Yes
Is there power to the
HSI probe?
Yes
Replace HSI probe
Is there a gas valve signal
No
from the ignition controller?
Yes
Is there power to the
gas valve (230V DC)?
Yes
Replace gas valve
Is the flame signal above
No
the minimum (1.2µA)?
Yes
Replace ignition controller
SHERBORNE
Check fan control wiring
No
connections, replace fan
No Check fan control wiring
connections, replace fan
Check wiring connections
No
to ignition controller
Check wiring connections,
No
replace ignition controller
Check wiring connections,
No
replace boiler main PCB
Check wiring to ignition
No
controllerl, replace ignition
No Check wiring to gas valve,
replace boiler main PCB
Check wiring from ignition
No
controller to flame probe,
replace ignition controller
31
controller
500001103/E