Water Heater Installation Manual
53 Page
PROBLEM SOLUTIONS
REMOTE CONTROLLER
Controller does not
display anything when
the power button is
turned on.
• Make sure the unit is supplied with power.
• Make sure the connection to the unit is correct. (pp. 37 and 38)
NOTICE:
When the unit has not operated for five minutes or more, the display of the
controllers turns off to conserve energy.
When the
controller turned
ON, STAND BY LED
is lit.
Built-in controller
An ERROR code is
displayed.
• Please see pp. 54 to 55.
Troubleshoong
Owner's Guide
ERROR CODES
• The units have self-diagnostic functions for safety and convenience when troubleshooting.
• If there is a problem with the installation or the unit, the error code will be displayed on the built-in
controller and remote controller. The green LED on the computer board will flash in a pattern shown on the
next page.
• Consult the table on the following pages for the description of each error code.
Error code indicator on the built -in
temperature controller
Error code indicator on the remote
controller
Error code on the computer board
Indicated by 1/2-second flashes on the Green LED.
240HX3/340HX3
Green LED
540HX3
Green LED
Example: If your unit has a “321” error code (which signifies an inlet thermistor failure)
• Indicator on the built-in controller or remote controller : “321” will be displayed
on the screen.
• Green LED on the computer board: The green LED on the computer board will indicate this code with two
flashes with a 1/2 second pause in between. The pattern will repeat with a three second pause between
patterns.
Error code
Error code Green LED
on on on on
on on
off off off off off
321