Technical data

8.1 The final 600mm of the mains cold water connection to the
appliance should be made in copper tube only.
8.2 The appliance is suitable for a mains pressure of up to 10 bar.
8.3 The appliance is fitted with a mains supply isolating valve. A
pressure reducing valve should be fitted if necessary.
8.4 The maximum hot water flow rate, via the flow regulator, is
nominally 18 l/m ±15%
8.5 It is suggested that long pipe runs to the taps or shower
should be insulated to prevent the rapid cooling of hot water
after the tap or shower has been turned off.
8.6 Hot and cold taps and mixing valves used with this
appliance must be suitable for operating at the available mains
pressure and up to 65°C.
8.7 Anti-syphonage arrangements are normally not necessary
except for some loose-head showers. See paragraph 8.10
following.
8.8 Thermostatically controlled shower valves will guard against
the flow of water at too high a temperature.
8.10 The head of a loose head shower must not fall closer than
25mm above the top edge of the bath to prevent its immersion
in bath water. Alternatively the shower must be fitted with an
anti-syphonage device at the point of the flexible hose
connections.
8.11 The supply of hot and cold mains water direct to a bidet is
permitted, subject to local Water Company requirements,
provided that the bidet is of the over-rim flushing type. The
outlet(s) should be shrouded and unable to have any temporary
hand held spray attached. No anti-syphonage arrangements are
necessary.
8.12 As the maximum temperature of the hot water heat
exchanger is limited by the control circuit, there is normally no
need for water treatment to prevent scale accumulation. In
exceptional circumstances a device to prevent scale formation
can be fitted.
8.13 Installation of a scale inhibitor assembly should be in
accordance with the requirements of the local Water Company.
An isolating valve to allow servicing should be fitted.
8.14 The temporary water hardness can be determined using a
standard test paper or by reference to the local water company.
8.15 A miniature expansion vessel (Zilmet R
1
/
2
, 160ml, 15bar),
available as an optional extra, should be fitted into the domestic
water supply circuit if there is evidence of water hammer.
8.16 A mini-expansion vessel must also be fitted if a back flow
prevention device or a water meter has been fitted to the cold
water mains supply.
9.1 The boiler requires a gas flow of 2.9m
3
/h (NG-G20) or
1.09m
3
/h (LPG-G31). Check that the supply system can
accommodate this together with any other appliances
connected to it.
9.2 A natural gas appliance must be connected to a governed
meter.
9.3 There must be a dynamic pressure of 20 mbar (G20) or 37
mbar (G31) at the inlet to the appliance. This is equivalent to a
pressure of 18.5 - 19.0 mbar (G20) or 35 - 35.5 mbar (G31) at the
inlet pressure tapping on the gas valve.
8. Domestic Water Supply
11
9. Gas Supply