Installation 4; Preparing The Installation; Technical Instructions For The Heating System; Direct Connection To The Heating Circuit Using The Integral Boiler Pump - Vaillant ecoMAX 646 Installation And Maintenance Manual

4 Installation
When installing, please observe the following points in
particular:
• Install the filling loop or other device in the return
• Ensure that the design of the system incorporates
a suitably sized by-pass or low loss header is installed
(as specified in paragraph 4.2)
When used with direct connection to an indirect DHW
cylinder using the connections provided:
• Install a primary loading pump
• Install a non-return valve in both heating and DHW
primary flows to prevent reverse circulation
• please also refer to section 4.3
4.1

Preparing the installation

Safety equipment for an emergency
• The outlet of the pressure relief valve must be suitably
terminated in accordance with BS 6798 or BS 6644.
• The boiler is suitable for connection to plastic central
heating pipes. It is preferred that the connections to
the boiler are made in copper for the first 1.5 metres
prior to the transition to plastic.
• Should a system be found to include non-oxygen barrier
pipe then it is essential that a plate heat exchanger be
installed in between the boiler and the non-oxygen
barrier pipe. It is essential that the boiler and the sys-
tem have provision for water make up and expansion.
4.2

Technical instructions for the heating system

Caution!
The schematics shown are for diagrammatical
representation only – the system may demand
further safety devices and depends fully on the
control system employed. Unvented cylinders
must comply with the requirements of Building
Regulations Document G 3.
Always refer to British Standards, Good Prac-
tice Guides and CIBSE guidelines
4.2.1 Direct connection to the heating circuit using
the integral boiler pump.
Pump layout; system dimensioning
The design flow rate of the ecoMAX 46 is optimally:
V = 2000 l/h at T = 20 K
flows through the boiler and system.
The resulting residual delivery head for the system design
is to be taken from fig. 4.2.
Setting the by-pass valve
In order to guarantee the minimum circulating water
volume of 1150 l/h through the appliance, a by-pass
valve must be fitted as a minimum requirement.
If an automatic type by-pass valve is fitted the operating
pressure should be able to be set between 250-400 mbar.
Installation and maintenance manual ecoMAX 646 / 0020020158_02
OS
1
3
3
230V~
3
53
Fig. 4.1 Example 1: radiator heating, direct feeding, integral
boiler pump
1 ecoMAX 646
2 integral boiler pump
53 automatic by-pass valve (not supplied)
OS outside sensor
Pressure [mbar]
900
850
residual delivery head without non-return valve
800
750
700
650
600
550
500
450
400
350
300
residual delivery head with non-return valve
(accessory. art-no. 306 715)
250
200
150
100
50
0
0 200 400 600 800
Fig. 4.2 Resulting characteristic curve (residual delivery head)
ecoMAX 646
4.2.2 Connection to heating circuit containing
a low loss header.
Pump layout in the primary circuit
The pump output must be set to 100% (in the DIA sys-
tem under point d.14).
Selection of the low loss header
A suitable WH model hydraulic switch (accessory) can
be selected with the aid of table 4.1.
A sufficiently large water volume (minimum circulating
water volume) is constantly supplied through the boiler
via the low loss header in conjunction with the pump
built into the boiler.

Installation 4

2
Design point
1000 1200 1400 1600 1800 2000
Volume flow [l/hr]
2200
11