Fault Finding - Bosch Worcester Greenstar Si Series User Instructions

FAULT FINDING

7 FAULT FINDING
If a boiler fault occurs, 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 mains indicator
Hot water temperature too
low
Hot water temperature too
high
Tab. 2
16
Cause
Thermostatic radiator valve(s)
set too low
Temperature control for
central heating 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
Water flow at tap too high
Temperature set too high
Water flow at tap too low
Remedy
B Increase thermostatic
radiator valve setting(s)
B Increase central heating
flow temperature control
setting
B Bleed radiators and
recharge heating system
B Turn down thermostatic
radiator valves/room
thermostat
B Reduce central heating
temperature by turning
down the Central Heating
control on boiler
B Check setting and adjust
B Switch off boiler at master
switch, wait a few seconds
then switch on again
B Check setting and adjust
B Reduce flow rate at tap
B Check setting and adjust
B Increase flow rate at tap
6 720 643 356a (2010/10)