Worcester Greenstar 4000 User Instructions page 18

Malfunction or failure
Does system pressure
increase when the
boiler is on?
NO
Is your system pressure regularly
dropping (i.e. you constantly
have to top up your boilers pressure)
NO
Your
boiler
is
fine
Fig. 13 Gassing flow chart
18
Is your system pressure constantly increasing even
when the boiler is off for extended periods of time?
NO
Does the system pressure increase to
YES
Contact
a
service
engineer
Does the problem persist?
Your
boiler
NO
is
fine
YES
Can you confirm that the filling
link is not stuck open/passing
YES
the high pressure red zone on the
pressure gauge?
NO
YES
Your
Contact
boiler
a
is service
fine
engineer
YES
water in any way?
YES NO
Contact
a
service
engineer
0010036321-001
Greenstar 4000 – 6 720 891 170 (2020/09)