Fault Finding - Bosch GREENSTAR HEATSLAVE II EXTERNAL 12/18 User Instructions & Customer Care Manual

FAULT FINDING

Problem
Desired room temperature
is not reached
Desired room temperature
exceeded by large amount
Temperature rises instead
of falling
No display or display unit
does not respond
Hot water temperature too
low
10
FAULT FINDING
Cause
Thermostatic radiator
valve(s) set too low
Room thermostat 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
Hot water temperature set
too low
Hot water not in timed
period on the programmer
GREENSTAR HEATSLAVE II EXTERNAL 12/18, 18/25 & 25/32
6 720 805 212a (07.2013)
Remedy
Increase thermostatic
radiator valve setting(s)
Increase room thermostat
setting
Increase CH flow
temperature control
setting
Bleed radiators and
recharge heating system
if system pressure is low
Turn down thermostatic
radiator valves / room stat
Check setting
Switch off boiler at master
switch, wait a few
seconds then switch on
again
Check setting
Check programmer
settings