Baxi Solo 12 HE Installation And Servicing Instructions page 13

Boiler
Fig. 9
1000mm
Boiler
Typical Low Head Installation
Fig. 10
Automatic Air
Vent
1000mm
Boiler
Fig. 11
Boiler
Fig. 12
Alternative Low Head Installation
© Baxi Heating UK Ltd 2006
Copper
Copper
0.5m
0.5m
Copper
1m
22mm
Open Vent
45°
15mm
Min
400mm
Cold
Min Head
Feed
150mm
Max
Pump
Return
22mm
Open Vent
45°
15mm
400mm
Cold
Min Head
Feed
Min
150mm
Max
Return
If Conditions Require,
This System Possible
22mm
200mm
Feed & Vent
Min
Pipe
Air
Separator
Pump
Return
6.0 System Details
Flow
6.3
Return
1. The sizes of flow and return pipes from the boiler
should be determined by normal methods, according to
the requirements of the system. The connection to the
boiler will accept 22mm pipe.
2. A 20 °C (36°F) drop in temperature across the system
is recommended for condensing boilers. Existing radiators
may be oversized and so allow this, but where radiator
sizing is marginal it may be advisable to retain a system
temperature drop of 11°C (20°F).
NOTE: On Solo 30 HE models 28mm pipe should be
used to connect to the boiler flow and return.
3. In systems using non-metallic pipework it is necessary
to use copper pipe for the boiler Flow and Return. The
copper must extend at least 1 metre from the boiler and
include any branches (Fig. 9).
Flow
6.4
1. Using a close couple arrangement the minimum head is
as shown in the diagrams (Figs. 10 & 11) subject to the
following conditions:
a) The pump being adjusted to give a 20°C drop across
the boiler.
b) The pump must be fitted on the flow.
c) The pump must be fitted in accordance with the
pump manufacturer's instructions.
d) The open vent pipe must be taken up from a tee in a
horizontal section of the flow pipe.
An alternative Low Head Installation
2. For heads below 400mm then a combined vent and
Pump
feed pipe may be connected. This must be a minimum of
22mm diameter. It is recommended that an air separator
Flow
is fitted when using a combined feed and vent pipe.
6.5
1. Providing that the cold feed and open vent pipe are
positioned correctly (e.g. the system is not prone to
pumping over, air entrainment etc.) the pump may be
fitted on the primary return pipe.
Flow
Pipework
Low Head Installation
(Fig. 12)
Pump
13