Potterton Promax 15 HE Installation And Servicing Instructions page 10

Boiler
Fig. 7a
Boiler
Fig. 8
Automatic
Air Vent
Boiler
Fig. 9
Boiler
Alternative Low Head Installation
Fig. 10
10
Supplied By www.heating spares.co Tel. 0161 620 6677
Copper
Copper
0.5m
0.5m
Copper
1m
22mm
Open Vent
45°
1000mm
15mm
Min
400mm
Cold
Min Head
Feed
150mm
Max
Pump
Return
Typical Low Head Installation
22mm
Open Vent
45°
15mm
400mm
Cold
1000mm
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 is 28mm (compression).
2. Due to space requirements within the boiler
outercase, pipework should comprise of solder
fittings.
3. 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).
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
Flow
(Fig. 7a).
6.4
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
preset boiler thermostat & TRV's only does not
produce the best results.
Pump 6.5
Flow
1. Using a close couple arrangement the minimum
head is as shown in the diagrams (Figs. 8 & 9)
subject to the following conditions:
a) The pump being adjusted to give an 20
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 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.
6.6
Flow
1. The Promax 24 HE is suitable for fitting with a
Thermal Store, for details please contact
Technical Enquires (08706 049 049). The Promax
15 HE is not suitable for fitting with a thermal
store.
Pipework
System Controls
Low Head Installation
(Fig. 10)
Thermal Stores
o C