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15
Symptom
Possible Cause
Remedy
ST9500C has a blank
LCD display
No power to the
heating system
Check that there is power to the
heating system
Fault in ST9500C
Call Installer
ST9500C indicates
that Zone 1 and/or
Zone 2 are
ON
, but
radiators are cold and/
or taps are running
with cold water.
Temperature controls
are switched off or set
too low
Check that the temperature controls
in the system are set to appropriate
levels
Boiler or other
system controls have
malfunctioned
Call Installer
ST9500C shows the
message ‘INTERNAL
FAULT’
Fault in ST9500C
Call Installer
Troubleshooting Guide
This is a quick guide to help you diagnose and cope with possible problems with
ST9500C. For further assistance, please contact your Installer.
FAQ AND TROUBLESHOOTING