Hamworthy Sherborne Series, Installation, Commissioning And Service Manual

Page: 39 / 48

HAMWORTHY HEATING LTD
SHERBORNE 500001103/E
Figure 12.4. Fault Finding Procedures.
Continued from
Fig 12.3
Boiler overheats while
system remains cool?
Boiler operates
noisily?
Insufficient water
circulation
Insufficient water
circulation
Temperature control
set too high
Gas control valve
set incorrectly
Gas control valve
faulty
Boiler operates
normally
Number of Flashes
1 Flash
2 Flashes
3 Flashes
4 Flashes
5 Flashes
Fault Condition
Ignition Lockout
Fan Fault (Running at wrong speed or running when should be stopped)
Condensate Drain Trap Blocked (Condensing models only)
Overheat (high limit thermostat tripped)
Premature flame detection (Flame sensing circuit fault)
Boiler Fault Indication
Certain boiler fault conditions are indicated by a sequence of flashes of the fascia fan running indicator
Scale build up in
boiler waterways
Check/replace pump, bleed
trapped air from the system
Check/replace pump, bleed
trapped air from the system
Adjust temperature
control knob setting
Check/replace gas control
valve assembly
Check/replace gas control
valve assembly
Descale boiler
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No
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