Domestic Hot Water (Model 308K)
The cast-iron heat exchanger has a
vitreous lining, with a maximum out-
put of 2.3kW/hr when the burner is
at high fire, e.g. with the OCV at its
highest setting.
Average hot-water production with
normal cooking activities over a 24
hour period is 400 litres.
If demands for hot water are likely to
be rather less than this amount, it is
permissible for a towel rail to be con-
nected, providing that the heated
surface area does not exceed .5 m
2
.
This cooker must be connected to
an open-vented system only and
although a direct system is permissi-
ble under certain circumstances in
known soft water areas, an indirect
system is to be much preferred. This
then allows for a suitable corrosion inhibitor to be added.
28mm diameter pipes should be used for the flow & return pipework, which should be arranged
so as to allow for gravity circulation. A maximum length of 5 metres each (i.e. distance between
the Rayburn and the storage cylinder) will ensure the hot water performance is maintained. No
thermostat valves or other restrictions must be fitted to this pipework.
The storage cylinder should be factory insulated and of the double feed type, with a capacity of
140 litres.
Interconnection plumbing with other heating products can be complicated and is not recom-
mended.
Under no circumstances must the 308K burner be alight unless the boiler is connected to the
hot-water system and filled with water.
Typical minimum clearances for a
flue termination
Typical hot-water system
