Worcester GREENSTAR 24i Junior Installation Instructions Manual page 68

FAULT FINDING AND DIAGNOSIS
Blue light Lockout
indication reset button
Slow flash Flashing
(mostly (reset
off, flashes required)
on)
Slow flash Flashing
(mostly (reset
on, flashes required)
off)
Fast flash Off
Fast flash Flashing
2 pulses No light
5 pulses No light
Tab. 27
68
Fault Possible solution/check
Ignition lockout B Gas present and at correct pressure?
B Gas valve
– Check that there is 35V d.c. to each solenoid
– Check the resistance of each solenoid:
B Combustion CO
B Flue condition.
– Blocked flue?
B Blocked condensate pipe or frozen condensate.
B Gas valve adjustment.
B Ignition electrodes/harness/connections.
– Check for condition and continuity
B Otherwise replace control board
Flue overheat B Heat exchanger baffles removed and not refitted.
Heat exchanger B Heat exchanger blocked
overheat
B Water pressure
B All air vented
B Pump/harness/connections.
B Water leaks/blockage
B Safety thermostats/low voltage wiring harness/connections
B Otherwise replace control board
Volatile lockout - B Temperature sensors
Fan does not run
– Check condition and continuity of leads/sensors
B Fan
– 230V a.c. across the live (purple) and neutral (brown)
B Fan lead
– Check continuity
B Code plug
– Is code plug missing or not inserted properly.
Internal fault Replace control board
Not a fault code Service mode selected to minimum, press service button to
return to normal
Not a fault code Service mode selected to maximum, press service button to
return to normal
Top solenoid = 380 Ω ± 10% (342 - 418 Ω)
Bottom solenoid = 190 Ω ± 10% (171 - 209 Ω)
level.
2
6 720 644 741a (2010/10)