Domestic Hot Water; Gas Supply; Electrical - Worcester C1 Installation And Servicing Instructions

8. Domestic Hot Water

It may be necessary to contact the local Water Company before
connecting the appliance.
Devices, which would prevent the flow of expansion water, must
not be fitted unless separate arrangements have been made. A
mini-expansion vessel kit is available as an optional extra.
The last 600mm of mains water pipe before the appliance must
be in copper.
The domestic hot water circuit of the appliance is suitable for a
mains pressure of up to 10 bar. A pressure reducing valve must
be fitted if necessary.
A mains water supply isolating valve is fitted.
The maximum hot water flow rate is set at the factory to 10
l/min giving a nominal temperature rise of 40°C with the
temperature control at maximum. Refer to Table 6. The
temperature rise, up to the maximum set by the user is
automatically maintained by the modulation of the heat input.
In winter it may be necessary to reduce the water flow at the tap
or shower to maintain the required delivery temperature.
It is recommended that long pipe runs to taps or showers are
insulated to prevent the rapid cooling of the water.
Hot and cold taps and mixing valves must be suitable for the
available mains pressure. If necessary, a pressure reducing valve
should be fitted.
No anti-syphonage arrangements are necessary for fixed head
showers.
The hose of a loose-head shower must be fixed so that the
shower head cannot get closer than 25mm to the top edge of the
bath to prevent its immersion in the water. Alternatively the
shower can be fitted with an anti-syphonage device at the
flexible hose connection.
Thermostatically controlled or pressure balancing shower valves
should be used where possible to give extra comfort and guard
against extreme temperature.
Hot and cold mains water direct to a bidet is, subject to the
approval of the local water company, permissible provided that
the bidet is of the overrim flushing type. The outlets must be
shrouded and unable to be fitted with a hand-held spray. No anti-
syphon arrangements are needed.
LIME SCALE: In areas of temporary hardness [ greater than
200ppm of calcium bicarbonate] it is suggested that a
proprietary scale reducer is fitted in the mains cold water
connection to the appliance. Installation of a scale inhibitor
assembly should be in accordance with the requirements of the
local Water Company. An isolating valve should be fitted to allow
servicing. The water hardness can be determined by reference to
the local Water Company.

9. Gas Supply

The appliance requires a maximum of 3.38 m
(G20) . Refer to Table 7.
A natural gas appliance must be connected to a governed meter.
The installation and connection of the gas supply to the
appliance must be in accordance with BS6891.
The meter and the pipework to the appliance must be checked,
preferably by the gas supplier, to ensure that a dynamic pressure
of 20mbar is available at the appliance [equivalent to about
18mbar at the gas valve inlet pressure connection] and that the
gas flow is adequate for all the installed gas appliances operating
together.

10. Electrical

Mains supply: 230V ~ 50 Hz 180watts. External fuse 3A.
Internal fuses F1-2A, F2-1.6A (20mm). Spare internal fuses are
supplied with the appliance. Refer to Fig 13.
The appliance must be earthed and it must be possible to
completely isolate the appliance.
The mains cable must be 0.75mm
Table 15 or 16.
The mains cable must be connected to the terminal ST12
marked L (red or brown lead), N (black or blue lead) and the
Earth stud (green or green/yellow lead) and secured with the
cable clamp. The Earth lead must be still be slack when the other
leads are taut. Refer to Fig 14.
The connection to the mains must be either : A 3A fused three-
pin plug and unswitched socket outlet (both complying with
BS1363) or a double pole isolator with a contact separation of
3mm in all poles and supplying the appliance and controls only.
A room thermostat or an externally mounted programmer must
be suitable for mains voltage operation, the leads must be
securely fixed in the cable clamps. Only double insulated mains
voltage controls not requiring an earth lead may be used. The
control board is accessed by removing the controls connections
cover. Refer to Fig 29.
A programmer or clock is available to fit into the facia. Full
instructions are sent with the control.
On very rare occasions an external frost thermostat might be
considered where parts of the system are remote from the
appliance. Refer to WHS Technical Department for more
information, Tel: 08705 266241.
Safety Check: If there is an electrical fault after installation check
for fuse failure, short circuits, incorrect polarity of connections,
earth continuity or resistance to earth.
9
3
/h of natural gas
2
(24x0.20 mm) to BS6500 -