Domestic Hot Water Supply - Worcester Highflow 400 RSF Installation And Servicing Instructions

9. Domestic Water Supply
9.1 The final 600mm of the mains cold water connection to the
appliance should be made in copper tube only.
9.2 The appliance is suitable for a mains pressure of up to 10 bar
2
(150 lb/in ).
9.3 The appliance is fitted with a mains supply isolating valve.
9.4 The maximum hot water flow rate is 18 l/m ±15% (3.9
gall/min ).
9.5 In winter, when the mains inlet water temperature is lower a
reduced flow rate, achieved at the tap, will increase the required
delivery temperature.
9.6 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.
9.7 Hot and cold taps and mixing valves used with this
appliance must be suitable for operating at a pressure of up to
2
10 bar (150 lb/in ).
9.8 Anti-syphonage arrangements are normally not necessary.
See paragraph 9.10 following.
9.9 Thermostatically controlled or pressure equalising shower
valves will guard against the flow of water at too high a
temperature.
9.10 The head of a loose head shower must not fall closer than
25mm (1in) 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.
9.11 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.
9.12 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.
9.13 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.
9.14 The water hardness can be determined using a standard
test paper or by reference to the local water company.
9.15 A miniature expansion vessel (Zilmet R
available as an optional extra, may be fitted into the domestic
water supply circuit if there is evidence of water hammer.
To fit the expansion vessel :
(i) Remove the front cover. Refer to Section 14 paragraph
14.2a, and Fig. 14.
(ii) Unscrew the hexagon headed screw located below the
flow switch. See Fig. 16.
(iv) Screw the expansion vessel into the connection using
thread sealant compatible with potable water.
13
1 / , 160ml, 15bar),
2