Rinnai E110CN Installation & Servicing Instructions Manual page 72

15.2.6
72
Error 05
check the ribbon
cable between
the control unit
and the display
the error persists
after reset
software error
control unit
control unit error
incorrect data will be detected in case of a poor
connection between the control unit and the
display. If necessary, replace the ribbon cable
between these two components.
.
replace the control unit. The controller will
automatically load the program into the new
control unit.