5.1.
CONNECTION TO THE OPEN CENTRAL HEATING SYSTEM
If the boiler is aimed to be integrated into an open central heating system, one of possible way how to
connect the boiler to the system is shown on Scheme 1b.
In case of
BioTec Plus
boilers, the boiler
pump obligatory
has to be
connected to the boiler
control unit
, in order to make turning on and off of
the pump depend
ing
on the temperature of the water in the boiler
, to avoid boiler condensation
.
Connection to an open central heating system requires the implementation of an open expansion
vessel (OPC) above the level of the highest heating body (radiator). If the expansion vessel is
situated inside the non heated room, it has to be insulated. The volume of the open expansion vessel
is about 7% of the volume of entire heating installation. The boiler
has
to be connected with one or
more CAS water accumulations, depending on its nominal power. It is recommended to connect
minimum 50 liters water accumulation to each 1 kW boiler nominal power (i.e. for the 45 kW boiler
minimal water accumulation should be 2250 liters) and always check the local regulation about the
needed minimum volume. The boiler should not be used without being connected to the water
accumulation (buffer) tank with needed min. volume. It must be connected to the CAS water
accumulation (buffer) obligatory through an 3-way mixing valve with actuator (protection valve) or 3-
way thermic valve (like ESBE VTC 512, VTC 531 (
60°C
), LTC 261, LTC 271 (60°C)).
5.2.
CONNECTION TO THE CLOSED CENTRAL HEATING SYSTEM
In closed heating system (as in example shown in Scheme 1a) it is
obligatory
to build in certified
safety valve with opening pressure of 2,5 bar, minimum seat diameter of 15 mm, minimum inlet
connection of 1/2", minimum exit connection of 3/4" and a membrane expansion vessel. Safety valve
and expansion vessel must be built in accordance with professional rules and any valve must not be
located between safety valve and expansion vessel and boiler.
The closed heating system must have
the installed expansion
vessel
of larger volume (
vessel
volume must be approx. 10% of the
heating
installation volume).
In all boiler types the heating pump
must be
connected to boiler control unit so
that the heating pump switching on and off would depend on water temperature in the boiler.
The boiler has to be connected with one or more CAS water accumulations, depending of its power. It
is recommended to connect 50 liters water accumulation to each 1 kW boiler power (i.e. for the 45 kW
boiler minimal water accumulation should be 2250 liters). The functioning of boiler control unit is
shown in Technical manual ''Digital boiler control unit BioTec Plus''. The boiler should not be used
without being connected to the water accumulation. It must be connected to the CAS water
accumulation obligatory through an 3-way mixing valve with actuator (protection valve) or 3-way
thermic valve (like ESBE VTC 512, VTC 531 (
60°C
), LTC 261, LTC 271 (60°C)).
Connection to the central heating system
Technical instructions
BioTec Plus
29