18 About the Boiler
●
When there is no further DHW demand, the burner
switches off and the 3-way valve remains in DHW mode
position during a wait time (5 minutes by default), so that
it can work more efficiently and provide more flexibility if
the taps are continuously turned on and off.
●
When the wait time has elapsed, the 3-way valve returns
to the Heating mode position and the boiler is ready to
provide heating.
Note
●
DHW priority: Whenever a hot water tap is turned
on in the home, the boiler begins to run in DHW
mode and the heating function is deactivated until
all the taps are turned off again.
●
When the boiler water pressure drops below
0.4 bar, follow the instruction“4.6 Filling the System”
to fill the boiler system.
Exhaust
Gas
Blow Fan
Air In
Air In
Ignitor
Gas
Valve
Gas
Inlet
DHW Out
Cold
Water In
Three
-way
Valve
DHW Heat
Exchanger
Circulation
Pump
Heat Exchanger
The following table lists the central heating temperature
range by k-factor setting value and the applicable outdoor
temperature range.
20 15
10
5
0
-10 -15 -20 -25
-5
20
30
40
50
60
50
70
80
90
4 3.5 3
2.5
2
1.5
1.2
0.6
1
0.2
Outdoor Temperature (ºC)
Outdoor Temperature Compensation
Heating flow temperature
(º
C
)
Note
To connect the outdoor temperature sensor to the
boiler, carefully follow the connection instructions
provided in the “12.4 Outdoor Temperature Sensor
2.6.3 Operating in DHW Mode
To operate the DHW mode:
1. Press the menu button (
) twice to access the DHW
temperature setting mode.
2. In the DHW Operation menu, select “1. DHW Set Temp” and
select a DHW temperature setpoint higher than current
DHW temperature.
●
When a hot water tap is turned on in the home, the boiler
flow meter detects DHW demand, the 3-way valve goes
to DHW mode and the circulation pump starts up, which
makes the water in the boiler primary circuit flow through
the DHW heat exchanger, producing instant hot water.
●
The electronic control modulates the burner output in
order to constantly produce hot water at the temperature
required.
Summary of Contents for NCB300-28K
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