Viessmann Vitodens 100-W B1HF Series Installation And Service Instructions Manual page 18

Installation sequence
Mounting the boiler and making connections
Fig. 7
1. Replace gaskets. Fit valves and gas shut-off valve.
Internal gasket diameter:
Gas connection Ø 18.5 mm
■
Connections on the heating water side
■
Ø 17.0 mm
Note
Gasket for gas connection is attached to the gas
shut-off valve.
2. Suspend the Vitodens from the wall mounting
bracket.
18
(cont.)
3 7
2.
3.
3. Note
Only remove the locking clip under the gas pipe
union nut once the appliance has been installed.
Clip is no longer required.
4. Torque settings:
■
■
When carrying out any work on gas connection fit-
tings, counterhold with a suitable tool. Never trans-
fer any forces to the internal components.
3 7
1.
4.
Union nuts G : 30 Nm
¾
Union nuts G : 24 Nm
½