Balanced Hot Water Supplies; Outlet Pipework; Secondary Circulation; Discharge Pipework - Heatrae Sadia ELECTROMAX Installation & Servicing Instructions Manual

5.4 Balanced Cold Water Supplies
It is advantageous in many mixer showers
or taps to have balanced pressure hot and
cold water supplies, in these instances the
balanced cold water supply should be teed
off the supply to the Electromax immediately
after the Cold Water Combination Valve (see
diagram 5, page 10).
Branches to cold outlets where drinking
water may be drawn should be taken
directly from the main supply before the
Cold Water Combination Valve to avoid
the possibility of warm expanded water
being drawn from cold taps.

5.5 Outlet Pipework

The pipework from the Electromax to the
hot outlet fittings should be in 22mm pipe
with short runs of 15mm pipe to showers
and basins. Small bore pipe can be used to
suit some taps, but runs should be kept as
short as possible. Pipe sizes may vary due
to system design.

5.6 Secondary Circulation

Secondary circulation is not recommended
for the Electromax as it is intended for
Off-Peak electrical operation. During other
periods the electricity supply is interrupted
to the immersion heaters so no reheating
will take place. Circulating the stored water
would gradually cool it to an unacceptable
temperature.

5.7 Discharge Pipework

It is a requirement of Building Regulations
that any discharge from an unvented system
should be visible and safely conveyed away
from the system without danger to persons in
or about the building where it is installed. The
discharge pipe should be fitted in accordance
with the requirements and guidance notes of
Building Regulations. Building Regulation G3
Requirements and Guidance section 3.9 are
reproduced in the following sections.
Information Sheet No.33 available from
the British Board of Agrement gives further
advice on discharge pipe installation. For
discharge pipe arrangements not covered
by G3 Guidance or BBA Info sheet No. 33
advice should be sought from either your
local Building Control Officer or Heatrae
Sadia. The discharge pipework supplied fitted
to the Electromax will convey any discharge
from the unvented cylinder Temperature
and Pressure Relief Valve and the sealed
system Pressure Relief Valve. A discharge
pipe will also be required from the Expansion
Valve fitted to the Cold Water Combination
Valve. Where practical this can be teed into
the discharge pipe from the Electromax. It
is recommended that an additional tundish
is fitted into this discharge pipe to give an
early indication of operation of the Expansion
Valve.
In some instances it may be possible to
discharge into an internal waste system and
soil stack. To do this a self sealing waste
valve must be fitted into the discharge pipe
after the tundish to prevent foul odours or
back-pressurisation from the waste system
entering the building via the tundish. In these
systems it is essential that the tundish is
fitted in a visible position as the final point
of discharge will not be visible. Consult
the manufacturer's recommendations with
respect to the correct fitting, orientation and
waste and soil stack materials selection. It
will also be necessary to get dispensation
from your local Building Control Officer to
discharge in this manner. Discharges from
an unvented system can be up to 95
several minutes, ensure any waste or soil
pipe connected to the discharge can
safely accept these conditions.
G3 REQUIREMENT
"...there shall be precautions...to ensure that
the hot water discharged from safety devices
is safely conveyed to where it is visible but
will not cause danger to persons in or about
the building."
Installation & Servicing Instructions
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