Technical data

Page 14
1.0 DESIGN
1.3 SYSTEM DETAILS
Pipe Sizing/Materials
The primary pipework connecting the boiler and the thermal store should be sized
to achieve a maximum of 8°C rise across the boiler or the maximum temperature
rise specified by the boiler manufacturer, whichever is smaller, but in any instance it
should not be less than 22mm copper tube.
Note: There should be no valves in the pipework connecting the boiler to the
BoilerMate A-Class.
The heating circuit operates on the normal primary boiler temperatures i.e. 82°C flow
and 71°C return. Therefore any traditional hot water radiators or convectors can be
used with this system and no special over-sizing of the heat emitters is necessary.
All the recommendations with regard to pipework systems in this manual are generally
based on the use of BS/EN Standard copper pipework and fittings.
However, we are happy that plastic pipework systems can be used in place of
copper internally as long as the chosen system is recommended for use on domestic
heating systems by the manufacturer and is installed fully in accordance with their
recommendations. We always recommend the use of barrier pipe for these systems.
Heating System
It is also essential that if an alternative pipework
material/system is chosen the manufacturer
confirms that the design criteria of the new
system is at least equivalent to the use of BS/EN
Standard copper pipework and fittings.
Boiler Size
It is only necessary to calculate the heating
requirements in accordance with BS 5449. The
allowances shown below should be added
for domestic hot water. The control system
automatically gives priority to hot water when
necessary.
Boiler Sited Below BoilerMate A-Class
Any temperature controlled boiler can be
used when the flow pipe from the boiler to the
BoilerMate A-Class rises continuously. No valve
shall be fitted in the primary flow or open vent.





Allowance for
domestic hot water
Model (kw)
BM125 3
BM145 3
BM185 4
BM210 5
BM225 6