Rinnai E110CN Installation & Servicing Instructions Manual page 75

15.2.9 Error 12
short-circuit 24 Volt
remove the
voltage from the
boiler and check
fuse F2
due to the 24 volt short-circuit inside or
outside the boiler, fuse F2 has blown. This
fuse is positioned in the control unit and can
be seen when the black covering lid has been
removed.
check the 24 Volt
connections
remove all plugs with 24 volt connections such
as: fan, pump, any three-port valve and 24 volt
plug to the connecting block
check the
disconnected
parts for wear
and tear
reconnect power to the control unit with the
disconnected parts.
which have been checked and are working
properly.
rectify the short-
circuit or replace
the short-circuited
component
Reconnect the parts
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