Viessmann C3HA, Installation And Service Instructions For Contractors

Page: 69 / 192

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6. Check the supply (flow) pressure.
Set value: 20 mbar.
Note
Use a suitable measuring device with
a resolution of at least 0.1 mbar to
check the supply pressure.
7. Record the actual value in the report
on page 184.
Take the action shown in the follow-
ing table.
8. Shut down the boiler, close the gas
shut-off valve, remove the pressure
gauge and close test nipple
A
with
the screw.
9. Danger
Gas escaping from the test
nipple leads to a risk of explo-
sion.
Check for gas tightness.
Open the gas shut-off valve, start the
boiler and check for tightness at test
nipple
A .
Supply pressure (flow
pressure) Action
less than 17.4 mbar Do not take the appliance into use, and notify the gas
supply utility.
17.4 to 25 mbar Start the boiler.
Above 25 mbar Install a separate gas pressure governor upstream of
the system and regulate the pre-charge pressure to
20 mbar. Notify your gas supply utility.
Checking the balanced flue system for tightness (annular gap
check)
A
A Combustion air aperture
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5618 294 GB
Service