Version 1.4
52 NCB-E Service Manual
Item
Description
Display
(P) Return Absolute
MAX Set-point
This menu may be used to make changes to the maximum return
temperature range the Return Control mode is in use. When configuring the
Custom mode in the Outdoor Reset Control mode, the return temperature
changes based on the return absolute MAX temperature range.
Setting range
Default
[MIN Set-point + 18°F(10°C)] - 158°F(70°C)
149°F(65°C)
For Celsius (°C) mode;
ex) at 65°C
For Fahrenheit (°F) mode;
ex) at 149°F
(Q) Return Absolute
MIN Set-point
This menu may be used to make changes to the minimum return temperature
range the Return Control mode is in use. When configuring the Custom mode
in the Outdoor Reset Control mode, the return temperature changes based
on the return absolute MIN temperature range.
Setting range
Default
68°F(20°C) - [MAX Set-point - 18°F(10°C)]
86°F(30°C)
For Celsius (°C) mode;
ex) at 30°C
For Fahrenheit (°F) mode;
ex) at 86°F
(R) AWS Operation
Pressure setting
This menu may be used to allow the boiler to maintain the space heating
system water pressure to ensure that a sufficient amount of water is in the
system. When the system pressure falls 4 PSI below the set value, the boiler
opens the makeup water feeding valve for a maximum of 2 minutes until
the system is filled and water pressure exceeds the set value. After filling
the system, the boiler runs the circulation pump for 15 seconds in the space
heating mode before completing the process. The makeup water feeding
valve operates only when there is no space heating or DHW demand.
Setting range
Default
12-30 PSI
6 PSI
If water pressure is 18 psi
(S) Initial operating
unit number setting
This menu may be used to set the number of water heaters initially activated
during DHW stand-by periods.
Setting range
Default
0-16
0
If initial operating water heaters
number is 3
