Honeywell Y9520Z Sundial RF2 Pack 5 User Manual page 30

Symptom
ST9520C shows the
message 'NO SIGNAL' and
a flashing radiator symbol
for one of the zones
DT92E shows a flashing RF
symbol
ST9520C shows the
message 'NO SIGNAL' and
a flashing flame symbol
Red light on BDR91T (if
installed) is lit continuously.
ST9520C shows the
message 'SENSOR FAULT'
and a flashing radiator
symbol
DT92E display shows '
' and a flashing spanner
symbol
ST9520C shows the message
'OPENTHERM FAULT'
30
FAQ AND TROUBLESHOOTING
Possible Cause
Your DT92E
batteries are
running low on
power.
RF communication
path between
ST9520C and
DT92E is blocked,
possibly by a metal
object.
RF communication
path between
ST9520C and
BDR91T is blocked,
possibly by a metal
object.
Fault with DT92E
Fault with the
Opentherm boiler.
The Opentherm
wiring is broken or
disconnected.
or
Opentherm has
been configured but
the wiring has not
been connected.
Remedy
Change the DT92E batteries
(see page 21 for how to do this).
Check direct path between both
products and re-position any
objects that may be blocking
the signal.
Relocate the DT92E, if possible.
Check direct path between both
product and re-position any
objects that may be blocking
the signal.
Call Installer
Enter Enquiry Mode as
described on page 14, use
the or buttons to scroll
round to a display that says
'OPENTHERM'.
A fault code may be shown on
the main display. Refer to the
Boiler manufacturer's instructions
for the required action.
If the display shows -- -- this
means there is a break in the
OpenTherm wiring between the
ST9520C and the boiler.
If in doubt, call your Installer.