Heating Mode; Cylinder Charging Mode; H Note - Vaillant ecoTEC VU 656/4 Installation And Maintenance Instructions Manual

5 Installation
5.1

Heating mode

In case of only one heating circuit to be operated
downstream of the low loss header, this one can directly
be controlled by the ecoTEC.
A suitable pump can be selected and installed
downstream of the low loss header. You can select a
pump that fits to your system. In case of systems with
multiple circuits please pay attention to the additional
control system accessories.
Hydraulic schematic drawing:
Heating circuit connection using low loss header
1
Fig. 5.3 Heating circuit connection using low loss header
Legend:
1 Boiler with internal pump
2 Low loss header
3 External heating pump
4 Consumer (e.g. heating circuit)
8 9 L N 3 4 5
X14
X6
Fig. 5.4 Electrical connection for heating pump downstream of
the low loss header
The settings for the internal pump are made at the
factory. The pump output can be reset to your own
requirements via diagnosis point "d.14", see Chap. 9.1.2.
Use the grey ProE plug to establish the electrical con-
nection with the external heating pump. To assign the
"external heating pump" function to the plug (1)
(additional relay) the value "2" must be specified at
diagnosis point "d.26" in the 2nd diagnosis level, see
Chap. 9.1.2.
16
4
3
2
X18
X13
X11
The low loss header ensures, in conjunction with the
boiler circulation pump, that a sufficiently high minimum
quantity of water is always circulating through the
boiler.
5.2

Cylinder charging mode

The electronics of the ecoTEC are designed in such a
way that one cylinder charging circuit and one heating
circuit can be connected directly without the need for
accessories. As the charging circuit is connected down-
stream of the low loss header this means that the size
of the cylinder and the specific cylinder primary pump
can be selected according to individual requirements.
h Note!
Observe that non-return valves or mixer
circuits may be required in order to eliminate
cross-flow to other circuits or the effects of
high temperatures from the charging circuit.
Hydraulic schematic drawing:
Hot water priority via low loss header
1
1
Fig. 5.5 Hot water priority via low loss header
Legend:
1 Boiler with internal pump
2 Low loss header
3 External heating pump
4 Consumer (e.g. charging circuit)
8 9 L N 3
X14
X6
Fig. 5.6 Electrical connection for cylinder charging pump
Installation and maintenance instructions ecoTEC 0020029173_01
4
3
2
X18
X13
4 5
1
X11