Version 2.21
40 NPE Service Manual
4.7.10 Setting the Operation Mode
1. Using the Front Panel, press and hold the Diagnostics Button
for over 5 seconds until “1.TST” is displayed.
2. Press the + (Up) button once to change the display to “2.OPR”.
3. Press the Information Button once to acess the Operation
Mode menu.
4. Press the + (Up) button once to set the water heater to
opearate at 1-stage MIN (“MIN.1”).
5. To set the water heater to operate at 2-stage MAX, press the +
(Up) button 3 times or until “MAX.2” is displayed.
6. To exit the Operation Mode and return the water heater to
normal operation, press the Reset button twice.
Information
Reset
Diagnostics
4.7.11 Error display and reset
1. Depending on the severity of the issue that is causing the
error, the water heater will either stop its operation or will only
be able to perform basic operations. A flashing red error icon
can be seen on the front panel along with the associated error
code.
2. When an error occurs while accessing other modes on the
front panel, press [RESET] to access the <error display mode>
while the error icon is flashing in order to view the error code.
3. While the panel is in the <error display mode>, the error icon
and code will flash in rotation at 1 second intervals.
4. The error code is displayed in 3 digits. (see below)
5. While in the <error display mode>, it is possible to access
the User Info, Service Info, Error History and Component Test
mode.
6. Press the [RESET] button once with the error code displayed
to reset the water heater. The front panel will display “RST” for
3 seconds and then release the error if the cause of the error
has been resolved.
7. If it is impossible to release the error, the error code will display
after 3 seconds.
4.7.12 Hot water temperature setting
1. At the <Normal operation mode>, press the [+] or [-] button to
access the <hot water temperature control mode>.
2. If the <hot water temperature control mode> is displayed, the
temperature setting value flashes.
→
The temperature value is
displayed while the temperature is being set.
3. Adjust the temperature with the [+] / [-] button. (Operated
depending on the temperature range: See the following table
below).
4. Pressing the [+] / [-] button for over 2 seconds acts as a
continuous key and will rapidly adjust the temperature.
5. It is impossible to increase the temperature above ~110°F
(43°C) while using the hot water(or only when at least 1 unit is
using hot water in a cascade system).
6. For high temperature applications, press the [+] + [-] button for
over 10 seconds to access temperature settings above 140°F
(60°C). (“HIGH” or “LOW” displayed for 2 seconds after setting)
7. Press the [Info] or [Reset] button once to return to the
<Normal operation mode>. (The temperature setting value is
maintained according to its last setting.)
8. If there is no button input for 5 seconds, then it automatically
returns to the <Normal operation mode>. (The temperature
setting value is is maintained according to its last setting.)
