Fault Finding - Worcester Greenstar 25Si User Instructions & Customer Care Manual

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 Group.
Problem
Desired room
temperature is not
reached
Desired room
temperature exceeded by
large amount
Heating stays on for too
long
No on/off indicator
Hot water temperature
too low
Hot water temperature
too high
WORCESTER BOSCH GREENSTAR 25Si/30Si
8 716 115 169b (09/2008)
Cause
Thermostatic radiator
valve(s) set too low
Temperature control for
CH flow on boiler set too
low
Air trapped in heating
system
Radiators are too hot
Clock is incorrectly set
Momentary power failure
Temperature set too low
Programmer setting
Water flow at tap too high
Temperature set too high

FAULT FINDING

Remedy
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
Switch off boiler at
master switch, wait a few
seconds then switch on
again
Check setting
Check setting
Reduce flow rate at tap
Check setting
FAULT FINDING
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