28
NIAS BTFS 24
Burner pressure (mbar)
Type of gas
Supply pressure
(mbar
nozzle Ø (mm)
diaphragm Ø
(mm)
Min Max
Natural gas
20
1.20
-
3.2
13.2
Butane
28
0.77
5.1
5.8
25.1
Propane 37
0.77
5.1
7.6
32.2
NIAS BTN 28
Burner pressure (mbar)
Type of gas
Supply pressure
(mbar
nozzle Ø (mm)
diaphragm Ø
(mm)
Min Max
Natural gas
20
1.20
-
3.0
13.7
Butane
28
0.75
-
4.9
26.8
Propane
37
0.75
-
6.9
34.6
NIAS BTFS 28
Burner pressure (mbar)
Type of gas
Supply pressure
(mbar
nozzle Ø (mm)
diaphragm Ø
(mm)
Min Max
Natural gas
20
1.20
-
2.8
13.3
Butane
28
0.75
-
5.1
27.3
Propane
37
0.75
-
6.8
35.2
3.7 Burner adjustment
All the instructions below must be solely performed by
qualified technicians.
Boilers are factory adjusted and tested.
Changes in the type of gas or adaptation to new supply
network conditions require adjustment of the gas valve.
Gas valve adjustment must be performed as follows:
A) Maximum power regulation
- check the value of the supply pressure (see table NOZZLES -
PRESSURES);
- remove cover C which protects the regulation screws of the
pressure regulator (pic. 27), located on top of the modulation
coil;
- set the CH water temperature to maximum;
- connect a U-shaped pressure gauge following instructions
shown in pic. 28;
- set the heat power regulator P1 (see pic. 22-29) to the
maximum by turning it CLOCKWISE;
- set the summer/OFF/winter/anti-freeze switch to winter;
- check that the room thermostat contact TA is closed;
- turn nut A (external) clockwise to increase and anti-clockwise
to decrease pressure.
B) Minimum power regulation
- disconnect power from modulation coil on gas valve;
- switch the burner on, check that “MINIMUM” pressure is set
according to “NOZZLES - PRESSURES” chart;
- adjust if needed by holding nut A still and turning screw B by
means of a 10mm screwdriver (CLOCKWISE to increase
pressure or ANTI-CLOCKWISE to decrease;
- restore power to modulation coil on gas valve.
C) Final operations
- check minimum and maximum pressures of gas valve;
- adjust as necessary;
- install plastic cover C;
- close all gas pressure test points;
- check for gas leaks.
pic. 27
MODULATION COIL
pic. 28
Connect the pressure gauge to MP
(TN – balanced flue only)
Connect the pressure gauge to MP and
RMP (TFS – forced draught versions
only)
MP = pressure test point
RMP = differential pressure test point
Summary of Contents for NIAS BTN 28
Page 1: ...NIAS INSTALLATION USE AND MAINTENANCE GB IST 03 C 167 01...
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