Baxi Solo 3 PFL 30 Installation & Servicing Instructions Manual page 8

Boiler
Fig. 5
Fig. 6
Automatic Air
Vent
Boiler
Fig. 7
Fig. 8
8
© Baxi Heating UK Ltd 2009
Copper
Copper
0.5m
0.5m
Copper
1m
22mm
Open Vent
45°
1000mm
15mm
Min
Cold
Feed
150mm
Max
Boiler
Return
Typical Low Head Installation
22mm
Open Vent
45°
15mm
Cold
1000mm
Feed
Min
150mm
Max
Return
If Conditions Require,
This System Possible
22mm
200mm
Feed & Vent
Min
Pipe
Air
Separator
Boiler
Pump
Return
Alternative Low Head Installation
Flow
Return
400mm
Min Head
Pump
Flow
400mm
Min Head
Pump
Flow
Flow
3.0 System Details
3.3 Pipework
1. If this appliance is being fitted to a system containing
plastic pipework, the flow switch kit part n
must be fitted.
2. The sizes of flow and return pipes from the boiler
should be determined by normal methods, according to
the requirements of the system.
3. An 11 °C (20°F) drop in temperature across the
system is recommended.
4. 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. 5). The copper pipe must not
be insulated.
3.4 System Controls
1. For optimum operating conditions, the heating system
into which the boiler is installed should include a control
system.
2. Such a system will comprise of a timer control and
separate room or cylinder thermostats as appropriate.
3. The boiler should be controlled so that it operates on
demand only.
4. Operation of the system under control of the boiler
thermostat only does not produce the best results.
5. A frost thermostat is fitted integrally to the appliance
controls and will protect the boiler from frost damage by
operating the burner when the water temperature in the
boiler drops towards freezing point. The boiler will fire
as necessary to maintain a temperature above freezing.
NOTE: The frost thermostat operates even if the boiler
thermostat is in the OFF ('0') position and it is necessary
therefore, if the system is drained, for the external
electrical and gas supplies to be isolated. It is
recommended that a label be affixed to the appliance to
draw attention to the fact that the system has been
drained.
3.5 Low Head Installation
For boilers up to 50,000 Btu/h output
1. Using a close coupled arrangement the minimum head
is as shown in the diagrams
(Figs. 6 & 7) subject to the following conditions:
a) The correct heat input.
b) The pump being adjusted to give an 11
across the boiler.
c) The pump must be fitted on the flow.
d) The pump must be fitted in accordance with the
pump manufacturer's instructions.
e) The open vent pipe must be taken up from a tee in
a horizontal section of the flow pipe.
Alternative Low Head Installation for all Solo 3 PFL
(Fig. 8)
2. If less height is available then a combined vent and
feed pipe may be connected. This must be a minimum
of 22mm diameter. It is recommended that an air
separator is fitted when using a combined feed and vent
pipe.
o 5107297
o C drop