Viessmann VITODENS 333, Service Instructions Manual

Page: 14 / 132

6. Check the supply (flow) pressure; it
should be
& 20 mbar for natural gas,
& 50 mbar for LPG.
Note
Use suitable test equipment with a
resolution of at least 0.1 mbar to
measure the supply pressure.
Record the actual value in the ser-
vice report.
Take the action shown in the table.
Supply (flow)
pressure for nat-
ural gas Supply (flow)
pressure for
LPG Remedy
below 17.4 mbar below 42.5 mbar Do not start up. Notify your mains gas or
LPG supplier.
17.4 to 57.5 mbar 42.5 to
57.5 mbar Start up boiler.
in excess of
57.5 mbar in excess of
57.5 mbar Install a separate gas governor down-
stream of the system and regulate the
pressure to 20 mbar for natural gas, or
50 mbar for LPG. Notify your mains gas
or LPG supplier.
7. Shut down the boiler, close the gas
shut-off valve, remove the pressure
gauge, and close test nipple
A
with the screw.
8. Open the gas shut-off valve and
start the boiler.
Danger
Gas escaping from the test
nipple leads to a risk of
explosion.
Check test nipple
A
for
soundness.
Further details regarding the individual steps
(cont.)
14
Initial start-up, inspection, maintenance
56
92
548
GB