Direct Venting (Two-Pipe System); General Installation Information; Installation Steps (Outline); Exhaust And Combustion Air Piping Material - Viessmann Vitodens 200-W WB2B Series Installation Instructions Manual

Vitodens Rigid and Flex Venting Systems Installation

General Installation Information

Installation steps (outline)

Exhaust and combustion air piping material

Use only the materials listed on the table entitled
"Approved materials for two-pipe system" on page 30 for
exhaust, combustion air intake pipe and fittings.
Cut the pipe end square and remove all burrs and debris

from joints and fittings.
If using CPVC special vent material for exhaust vent pipe

and ABS / PVC / CPVC for combustion air intake pipe,
all joints must be properly cleaned, primed and
cemented. Use only cement and primer approved for
the use with the pipe material. See table entitled
"Approved materials for two-pipe system" on page 30
for approved solvent cement material.
CAUTION
For solvent cement and primer:
Use only in well ventilated areas

Do not use near flame or open fire

Use only the solvent cement and primer appropriate

for the venting material being used
Solvent cements for plastic pipe are flammable liquids

and must be kept away from all sources of ignition
For rigid PP(s) venting system only; Venting material

must be ULC S636 or UL 1738 listed, (see page 33 for
listed manufacturers).
No low point is allowed in the exhaust vent pipe system,

unless a proper drain pipe is used to allow condensate
to drain.
WARNING
Ensure that the entire venting system is protected from
physical damages. A damaged venting system may
cause unsafe conditions.
WARNING
The venting system is approved for indoor installations
only. Do not install the venting system outdoors.

Direct Venting (Two-pipe System)

Route vent pipe as directly as possible and with as few

bends as possible to the boiler.
Condensate must drain from the flue pipe to the boiler.

Ensure a suitable gradient of at least 3º [approx. 2 in.
per 3.3 ft. (50 mm per 1 m)].
Use a hacksaw or sheet metal snips (for stainless steel)

to cut pipes to length (if necessary). Use a file to smooth
rough edges. Pipe must be round and not bent into an
oval shape.
Check proper location of gaskets in rigid PP(s) pipe

collars. (Only use supplied parts with the polypropylene
venting system.)
Apply water to lubricate the joint ends of the vent pipe
collar and if used, the air intake pipe collar.
Slide pipes into each other with a gentle twisting motion.

IMPORTANT
When cutting pipes to length, debur and clean pipes.
In conjunction with these instructions, follow the
installation instructions supplied by the special venting
manufacturer.
All piping must be fully supported. Use pipe hangers at

intervals specified by manufacturers to prevent sagging
of the pipe.
The exhaust vent/air intake pipe and fittings must be

securely supported by a support system suitable for the
weight and design of the material employed. Contact
your local vent material supplier for more information
specific to your installation(s).
IMPORTANT
Ensure that the exhaust vent/air intake pipes are properly
supported. The Vitodens boiler is not designed to support
the weight of the exhaust vent/air intake pipe system.
Field supplied increaser fittings (transition) should

always be inserted in vertical sections of pipe to
prevent accumulation of condensate in the vent pipe.
The total equivalent length specified for a two-pipe

system is the total of the combined length of the
exhaust vent/air intake pipe system. Do not exceed
these maximum lengths.
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