System Design Considerations - Viessmann VITODENS 200-W Technical Data Manual

System Design Considerations

IN THE COMMONWEALTH OF MASSACHUSETTS...
-this product shall be installed by a licensed plumber or gas fitter.
-the flexible connector (if used) cannot exceed 36".
-any level type shutoff used must be of tee handle type.
Boiler location
As a direct vent appliance, the Vitodens
200-W can be installed for room air
independent operation (sealed combustion)
regardless of size and ventilation method of
the room in which it is located.
The Vitodens 200-W can be installed, for
example, in the main living area of a house,
in non-ventilated utility rooms, cupboards,
closets and alcoves with no clearance
required from combustible materials, as well
as in attics with a direct outlet for the flue
gas/fresh air system. Follow all local and
national codes.
Flue gas system
Viessmann PPS (Polypropylene) concentric
flue gas/fresh air systems for room air
independent operation (sealed combustion)
and side wall venting are tested to ANSI
Z21.13 - CSA 4.9 - 2000 standards and are
certified together with the Vitodens 200-W
boiler as a constructional unit.
The Vitodens 200-W boiler may also be
vented vertically, using an AL29-4C® special
stainless steel, single-wall, room air
dependent venting system (UL listed for
category IV).
For a more detailed description of the direct
vent and single-wall vent system, please
refer to the Vitodens 200-W Venting
System Installation Instructions.
Flue gas temperature protection
Flue pipes used for the Vitodens 200-W are
suitable for max. flue gas temperatures of
up to 230°F / 110°C.
No flue gas temperature protection is
required as the maximum permissible flue
gas temperature is not exceeded in any
operating condition or in the event of
malfunctioning.
Low water cut-off
A low water cut-off may be required by
local codes. If the boiler is installed above
the radiation level, a low water cut-off
device of approved type must be installed in
all instances. An approved type low water
cut-off device must be provided by the
heating contractor. Do not install an
isolation valve between the boiler and the
low water cut-off.
System layout
H The max. boiler water temperature for
space heating and DHW production is
–165°F / 74°C for models WB2B 19 to
60 or –176°F / 80°C for models WB2B 80
and105.
To minimize distribution losses,
Viessmann recommends that the heating
and domestic hot water systems be based
on a maximum boiler supply temperature
of 158°F / 70°C.
H Due to the low return temperatures
required for gas condensing, no mixing
valves should be used in the heating
circuit whenever possible. If mixing valves
are required, e.g. for multi-circuit systems
or underfloor heating systems, only 3-way
mixing valves must be used.
Do not use 4-way mixing valves with
condensing boilers.
Water connections
Vitodens 200-W boilers can be used in any
fully pumped hot water heating system.
Minimum system pressure is 0.8 bar/12 psig.
Chemical corrosion protection products
Corrosion does not typically occur in sealed
heating systems which have been correctly
installed and are correctly operated.
Many manufacturers of plastic pipes
recommend the use of chemical additives.
In this case, only those commercially
available corrosion protection products
approved for boilers with domestic hot
water heating via single-wall heat
exchangers (instantaneous plate heat
exchangers or DHW tanks) must be used.
Underfloor heating systems
For underfloor heating systems Viessmann
recommends the use of plastic tubing with
an oxygen diffusion barrier in order to
prevent the diffusion of oxygen through
tubing. If plastic tubing without an oxygen
diffusion barrier is used in underfloor
heating systems, Viessmann recommends
that such systems be separated from the
boiler with a heat exchanger.
Underfloor heating systems and heating
circuits containing a very large volume of
water must be connected to the boiler via a
3-way mixing valve; please refer to the
applicable installation example in this
manual.
Installation Examples
Oxygen diffusion barrier
underfloor tubing
The boiler warranty does not cover leaks
resulting from corrosion caused by the use
of underfloor plastic tubing without an
oxygen diffusion barrier. Such systems must
have the non-oxygen diffusion barrier tubing
separated from the boiler with a heat
exchanger. Viessmann recommends the use
of underfloor plastic tubing with an oxygen
diffusion barrier.
Water quality
Treatment for boiler feed water should be
considered in areas of known problems,
such as where a high mineral content and
hardness exist. In areas where freezing
might occur, an antifreeze may be added to
the system water to protect the system.
Please adhere to the specifications given by
the antifreeze manufacturer. Do not use
automotive silicate based antifreeze. Please
observe that an antifreeze/water mixture
may require a backflow preventer within the
automatic water feed and influence
components such as diaphragm expansion
tanks, radiation, etc. Maximum antifreeze
content is 50% for the Vitodens 200-W
boiler. Do not use antifreeze other than
specifically made for hot water heating
systems. System also may contain
components which might be negatively
affected by antifreeze. Check total system
frequently when filled with antifreeze.
Advise system operator/ultimate owner that
system is filled with a glycol mix.
The heating contractor must provide a
MSDS (Material Safety Data Sheet) for the
antifreeze used to the system
operator/ultimate owner.
Warranty
Our warranty does not cover damages
resulting from the following:
– installation or service by unqualified and
unlicensed personnel.
– attempting to perform any repair work on
the boiler other than that mentioned in the
boiler literature.
– tampering with or attempting, without
Viessmann permission, to readjust
the factory settings of the
–combination gas valve
–combustion air opening of the
burner blower
– leaks resulting from corrosion caused by
the use of underfloor plastic tubing
without an oxygen diffusion barrier.
For detailed warranty information, please
read warranty sheet supplied with product.
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