FAULT FINDING
Problem Cause Remedy
Switch off boiler at master
switch, wait a few
seconds then switch on
again
Desired room temperature
is not reached
Thermostatic radiator
valve(s) set too low
Room thermostat set too Increase room thermostat
low setting
Temperature control for
CH flow on boiler set too
low
Air trapped in heating
system
Desired room temperature
exceeded by large amount
Temperature rises instead
of falling
No display or control unit
does not respond
Hot water temperature too
low
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
Heatslave tank not up to
temperature
Increase thermostatic
radiator valve setting(s)
Increase CH flow
temperature control
setting
Bleed radiators, if fitted to
a sealed system recharge
heating system
Turn down thermostatic
radiator valves / room stat
Check setting
FAULT FINDING GREENSTAR HEATSLAVE EXTERNAL12/18 - 18/25 - 25/32
8 716 113 390e (03.2010)
10
USING YOUR
BOILER
Check hot water
temperature control
setting
Check programmer
settings
Allow time for Heatslave
tank to reach temperature