Checking The Minimum Pressure; Completion; Gas Settings Table; Changing The Type Of Gas - Ariston NEXT SFT 14 User Manual

4.4.3. Checking the minimum pressure

1. Close the gas isolation valve
2. Loosen screw "a" and attach the manometer connection
pipe into the pipe tap.
3. Open the gas isolation valve
4. Activate the appliance by opening a D.H.W. tap.
5. Press the SW2 button (on the P.C.B.), the appliance is
forced to the minimum power.
The display will show CL
Default value = 0
6. The burner pressure should correspond to the value
shown in the "Gas Settings" table, in relation to the type
of gas for which the appliance is designed. If it does not
correspond adjust the potentiometer P1.
To save the change, press the SW2 button.
7. To exit, press SW3 and SW2 buttons simultaneously or
press the ON/OFF button.
8. Close the D.H.W. tap.
9. Close the gas isolation valve
10. When the check is over, tighten screw "a" and make sure
it is securely in place
11. Open the gas isolation valve and check for tightnes.
4.4.4. Checking the gas rate
Ensure the appliance is gas rated, to check the appliance
is burning the correct volume of gas at both maximum and
minimum rate. (see 4.5 Gas settings table).
Note: Permissible tolerance -5% / +10%

4.4.4. Completion

Once installation is complete, commission the appliance as
instucted in Section 4, page 19).
Instruct the end user on the following:
• How to switch off the appliance quickly and indicate the
position of the electrical supply isolator.
• Explain to the end user that if the appliance is not to
be used for long periods that it is advisable to drain the
appliance to prevent damage in the event of it freezing.
• Advise the end user that to ensure safe and effective
operation, the appliance must be serviced once a year by a
Gas Safe registered engineer.
• Finally, leave these instructions with the end user.

4.5 Gas settings table

lower Wobbe index (15°C, 1013 mbar)
Gas inlet pressure
Gas Burner Pressure MAX
Gas Burner Pressure MIN
Main Burner jets
Ø burner jets
Max/min consumption
(15°C, 1013 mbar)
(NG = m3/h) (LPG = kg/h)

4.6 Changing the type of gas

The appliance may be adjusted so that it may be used with
LPG (G31) instead of Natural Gas (G20) or vice-versa. The
adjustment must be performed by a Gas Safe Registered
enginner using the special conversion kit.
CL and a value from -9 to +9.
MAX
MIN
NEXT SFT 14
G20 G31
MJ/m 3 45.67 70.69
mbar 20 37
mbar 10.8 10
mbar 3.7 3.3
nr. 15
mm 1.5 1.1
2.96 2.17
0.63 0.47
4. commissioning
21