Balanced Cold 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.
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 Regulation G3
that any discharge from an unvented system is
conveyed to where it is visible, but will not cause
danger to persons in or about the building.
The tundish and discharge pipes should be
fitted in accordance with the requirements and
guidance notes of Building Regulation G3. The
G3 Requirements and Guidance section 3.50 -
3.63 are reproduced in the following sections of
this manual. For discharge pipe arrangements
not covered by G3 Guidance advice should
be sought from your local Building Control
Officer. Any discharge pipe connected to the
pressure relief devices (expansion valve and
temperature/pressure relief valve) must be
installed in a continuously downward direction
and in a frost free environment.
Water may drip from the discharge pipe of
the pressure relief device. This pipe must be
left open to the atmosphere. The pressure
relief device is to be operated regularly to
remove lime deposits and to verify that it is
not blocked.
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."
Notes:
Discharge pipe-work D2 can now be a plastic
pipe but only pipes that have been tested to a
minimum 110°C must be used.
Discharge pipe D2 can now be plumbed into
the soil stack but only soil stacks that can
handle temperatures of 99°C or greater should
be used.
The following extract is taken from the latest
During other G3 Regulations
Discharge pipe D1
3.50 Safety devices such as temperature relief
valves or combined temperature and pressure
and pressure relief valves (see paragraphs 3.13
or 3.18) should discharge either directly or by
way of a manifold via a short length of metal
pipe (D1) to a tundish.
3.51
should be not less than the nominal outlet size
of the temperature relief valve.
3.52
be sized to accept and discharge the total
discharge form the discharge pipes connected
to it.
Installation & Servicing Instructions
The diameter of discharge pipe (D1)
Where a manifold is used it should
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