Hydraulic Connection - Viessmann VITODENS 200-W Type B2HA Technical Manual

Design information
1500
A Condensate drain
B 4 x condensate inlet with drain plug
4

4.3 Hydraulic connection

General information
System design
Viessmann condensing boilers can generally be installed in any fully
pumped hot water heating system (sealed unvented system).
Connection sets with an integral circulation pump are available as
accessories.
Minimum system pressure 1.0 bar (0.1 MPa).
The boiler water temperature is limited to 82 °C.
To minimise distribution losses, we recommend sizing the heat distri-
bution system to a max. flow temperature of 70 °C.
The heat generator must be correctly sized and selected.
Chemical anti-corrosion agents
According to VDI guideline 2035, the design of heating systems
must ensure they are sealed against corrosion. Additives in the heat-
ing water (additives, chemicals) as corrosion protection measures
are normally not necessary.
Exception: In systems without system separation, for example, addi-
tives can be considered.
Heating circuits
For heating systems with plastic pipes, we recommend the use of
impermeable pipes to prevent the diffusion of oxygen through the
pipe walls.
Provide system separation in heating systems with plastic pipes that
are permeable to oxygen (DIN 4726). A separate heat exchanger for
this purpose is available.
Install a dirt separator in underfloor heating systems. See
Viessmann Vitoset pricelist.
Underfloor heating systems and heating circuits with very large
water content (>15 l/kW) should be connected to the condensing
boiler via a 3-way mixer. See technical guide "Control of underfloor
heating systems" or the relevant sample applications.
Install a temperature limiter in the flow of the underfloor heating cir-
cuit to restrict the maximum temperature. Observe the requirements
of DIN 18560-2 [or local regulations].
VIESMANN
74
(cont.)
A
B
204
262
279
Specification
Rated voltage 230 V~
Rated frequency 50 Hz
Power consumption 70 W
IP rating IP 20
Permissible medium tem- +65 °C
perature
Max. head 50 kPa
Max. pump rate 500 l/h
Alarm contact Changeover contact (floating), breaking
capacity 250 V/4 A
Plastic pipework for radiators
We also recommend the use of a temperature limiter to restrict the
maximum temperature for plastic pipework in heating circuits with
radiators.
Safety valve
A safety valve in accordance with TRD 721 is part of the heating cir-
cuit connection set (accessories) (opening pressure 4 bar
(0.4 MPa)).
Route the discharge pipe in accordance with EN 12828 into a drain
outlet (drain outlet kit available as an accessory). The drain outlet
incorporates a siphon as a stench trap.
Low water indicator
According to EN 12828, a low water indicator can be omitted for boil-
ers up to 300 kW, as long as heating can be reliably prevented when
there is a water shortage.
Viessmann condensing boilers are equipped with a low water indica-
tor (boil-dry protection). Tests have verified that the burner will be
automatically switched off in the event of water shortage due to a
leak in the heating system and simultaneous burner operation,
before the boiler or the flue system reaches unacceptably high tem-
peratures.
Attic heating centre
The installation of a low water indicator, specified as compulsory to
EN 12828, is not required when installing the Vitodens in an attic
heating centre.
Vitodens condensing boilers are protected against water shortage in
accordance with EN 12828.
Water quality/frost protection
Unsuitable fill and top-up water increases the level of deposits and
corrosion and may lead to boiler damage.
Observe VDI 2035 regarding the quality and volume of heating
water, including fill and top-up water.
VITODENS 200-W