Ariston CLAS HE R 12 Installation And Servicing Instructions page 14

installation
Note:
• The distance between the cold feed and the open
vent pipe shall be no more than 150mm.
• The cold feed must be inverted as shown.
• The open vent pipe must be a minimum of mm
diameter.
• The cold feed pipe must be a minimum of 15mm
diameter.
• The cold feed and open vent pipes must rise
continuously and be unrestricted.
• The minimum distance from the top of the boiler
to the bottom of the F & E tank shall be no less
than m. Whilst the maximum distance shall be
not more than 7m.
• The distance between the bottom of the F & E
tank and the highest point of the open vent must
be no less than 500mm.
• The flow and return pipes from the boiler must
rise continuously and be unrestricted.
• The supply of water to the F & E tank should be
taken from the mains water supply via a suitable
float operated valve. While the supply from the F
& E tank to the boiler/heating circuit (via the cold
feed) shall be unrestricted.
• The F & E tank must be adequately supported
and installed in accordance with relevant Building
Regulations.
Pressure Loss Graphs through the boilers
mWH
5.0
4.5
4.0
3.7 mWH
3.5
3.0
2.65 mWH
2.5
2.0
1.5
1.3 mWH
1.0
0.5
0
14
18 kW
12 kW
100 200 300 400 500
555 l/h = 20 @ 12.9 kW
Pump specification
The pump should be fitted on the flow pipe from
the boiler and have isolating valves each side. A
variable duty pump should be set to give a tempe-
rature differential of no greater than 0ºC.
Draining tap
A draining tap must be provided at all the lowest
points of the system which will allow the entire
system to be drained. A drain tap must also be
installed on the flow and return pipes immediately
above the boiler to ensure complete draining of the
primary flow and return is possible.
Drain taps shall be to the current standard of BS
879.
Sealed water systems
A sealed system kit is available from Ariston. Installa-
tion instructions are supplied with the kit.
12-18 kW
600 700 800 900 1000 1100 1200 1300 1400
1118 l/h = 20 @ 26.0 kW
821 l/h = 20 @ 19.1 kW
24 kW
l/h