Gas type selection
Table 49 Program values, factory default settings and ranges.
Control board diagnostics
1. Press ON/OFF button
2. Press and hold simultaneously buttons
seconds, until display reads P2.
to enter P2 adjustment. The current setting will appear on
the display. If not, repeat process.
4. Press and release the
button on the control panel until the
display reads 'P4'. You are now in the diagnostic mode of the control
5. When the display reads 'P4', press and release the
again and the display should read 'E'.
6. Use the
button on the control board to cycle through
different diagnostic modes available.
7. Once in the selected diagnostic mode of your choice, press and
button to display the diagnostic information.
EXAMPLE: to read the flow rate in gallons per minute while the unit is
flowing water, cycle to the '3d' mode and press the
reading of 25 on the display would indicate the heater is reading a flow
rate of 2.5 gallons/minute.
8. Once the information is obtained, press the
return to the diagnostic mode menu and scroll to addition diagnostic
9. Press ON/OFF button to turn OFF the appliance and back ON again to
return heater to normal function.
LP or NG
button again to
note: reducing P1 values below maximum will
reduce maximum power of the appliance.
dE turns back light off after 60 seconds from
last button pushed, ON turns backlight on
Runs secondary fan and primary fan when P9
is selected by depressing the "P" - button
This menu is only available when cascade
Contact Bosch Water Heating for details.
Heat exchanger water temperature
Bypass control monitor (°F) [0d - 2d]
Table 50 * Settings define from factory
Maintenance and service | 45
see chapter 4.14, page 36
see chapter 4.3.8, page 22
see chapter 6.5, page 40
see chapter 7.7, page 45
contact Bosch for details
Preset from factory.
Contact Bosch for details.
mode is selected CC.
Entry/Exit into sub-modes
Inlet water temperature (°F)
Outlet water temperature (°F)
Water flow (gallons/min)
Fan speed (Hz)
Burner power (%)
Maximum power (kW)
Back flow temperature (°C)
Exhaust temperature (°C)
Most recent error/failure
2nd most recent error
3rd most recent error
4th most recent error
5th most recent error
6th most recent error
7th most recent error
8th most recent error
9th most recent error
6 720 805 440 (2014/11)