Burner Adjustment When Connecting Multiple Flues To A Shared Flue System - Viessmann VITODENS 111-W Installation And Service Instructions Manual

Further details regarding the individual steps
8. Shut down the boiler, close the gas
shut-off valve, remove the pressure
gauge and tighten screw in test con-
nector A.
9. Open the gas shut-off valve and start
the appliance.
Danger
Gas escaping from the test
connector leads to a risk of
explosion.
Check gas tightness at test
connector A.
Supply pressure (flow pressure)
For natural gas
below 17.4 mbar
(1.74 kPa)
17.4 to 25 mbar
(1.74 to 2.5 kPa)
above 25 mbar
(2.5 kPa)
Burner adjustment when connecting multiple flues to a shared
flue system
When connecting several
Vitodens 111-W to a shared flue system:
Adjust the burner setting of each con-
nected boiler by a correction factor to
match the flue system.
System conditions:
■ Shared flue in shaft 7 100 mm
■ Balanced flue connection line from
boiler to shaft 7 80/125 mm
For LPG
below 25 mbar
(2.5 kPa)
25 to 47 mbar
(2.5 to 4.7 kPa)
above 47 mbar
(4.7 kPa)
Commissioning, inspection, maintenance
(cont.)
Note
The maximum pressure drop between
the gas shut-off valve and test connector
A at the gas train is 0.5 mbar (50 Pa).
Measures
Do not start the boiler. Notify your gas
supply utility or LPG supplier.
Start the boiler.
Install a separate gas pressure governor
upstream of the system and regulate the
flow pressure to 20 mbar (2.0 kPa) for
natural gas or 37 mbar (3.7 kPa) for LPG.
Notify your gas supply utility or LPG sup-
plier.
■ Minimum shaft cross-section
– Square 175 x 175 mm
– Round 7 195 mm
■ Height between floors min. 2.5 m
■ Max. 6 boilers with the same rated
heating output connected to the flue
system
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