Recommended Venting Practice; Leak Test (For Coaxial Venting Systems Only) - Viessmann Vitodens 200-W WB2B Series Installation Instructions Manual

Vitodens Rigid and Flex Venting Systems Installation
General Rigid Venting Installation

Recommended venting practice

Leak test (for coaxial venting systems only)

Viessmann recommends that the heating contractor perform
a simplified leak test during boiler start-up. For this purpose
it is sufficient to measure the CO
combustion air in the annular gap of the air intake pipe.
The vent pipe is considered sufficiently leak-proof if a CO
concentration in the combustion air no higher than 0.2%
or an O concentration no lower than 20.6% is measured
2
relative to a starting O concentration of 20.9%.
2
(continued)
concentration of the
2
2
When installing a venting system the following
recommended venting practices apply:
Keep length and number of 90º elbows to a minimum.

Try not to use back-to-back 90º elbows.

Use 45º elbows where possible to minimize the number

of 90º elbows in case redirection of flue gas is required.
The special vent system shall not be routed into,

through, or within any other vent such as an existing
masonry or factory-built chimney.
Exception:
A masonry chimney flue may be used to route the venting
system only if no other appliance is vented in the same flue.
IMPORTANT
Route the flue gas connection to be free of load and
torque stresses. We recommend fitting an on-site support
immediately downstream of the boiler flue connection.
If higher CO values or lower O
2
inspect the venting system thoroughly.
Continuous short cycling of the boiler can indicate a leaking
venting system.
Note: The vent pipe adaptor comes with two measurement
ports, one for combustion air intake measurement
and one for flue gas measurement.
General Information
values are measured,
2
13