FAULT FINDING
Problem
Cause
Remedy
Switch off appliance at
master switch, wait a few
seconds then switch on
again
Check setting
Reduce flow rate at tap
Desired room
temperature is not
reached
Thermostatic radiator
valve(s) set too low
Temperature control for
CH flow on boiler set too
low
Air trapped in heating
system
Desired room
temperature exceeded by
large amount
Heating stays on for too
long
No on/off indicator
Hot water temperature
too low
Radiators are too hot
Clock is incorrectly set
Momentary power failure
Programmer setting
Water flow at tap too high
Increase thermostatic
radiator valve setting(s)
Increase CH flow
temperature control
setting
Bleed radiators and
recharge heating system
Turn down thermostatic
radiator valves / room
thermostat
Reduce central heating
temperature on boiler
Check setting
FAULT FINDING
WORCESTER BOSCH GREENSTAR 24i/28i Junior
8 716 107 338b (11.05)
14
MAI
NTE
NANCE
This table gives information on basic operating
system problems.
In the unlikely event of a boiler fault please read
the following page thoroughly before contacting
Worcester Bosch.
