10
6.2.3 Balanced Cold Water Supply
It is also recommended to install a drain valve (not
supplied) in the lowest point of the cold water feed to
the water heater. This allows the water heater to be
drained in a controlled manner should this become
necessary.
6.3 Hot Water Outlet
The hot water pipework is to be directly connected to
Should a thermostatic mixing valve be required to limit
the temperature delivered to the how water taps, a risk
assessment for the prevention of Legionella must be
carried out. The mixing valve must be installed accord-
ing to the manufacturers instructions, ensuring none of
the safety equipment has been isolated, (i.e. make sure
the connection to the thermostatic mixing valve is taken
after the safety equipment of the inlet group).
6.3.1 Thermostatic Mixing Valve
6.4 Discharge Pipes from Safety
Devices
6.4.1 Discharge Pipe D1
The temperature and pressure relief valve must be
discharged directly or by way of a manifold via a short
length of metal pipe (D1) into a tundish; and the
discharge pipe 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 and this pipe must be left open to
the atmosphere.
6.4.2 Discharge Pipe D2
For a detailed description of the discharge pipework D2
(see Section 5.10.1).
6.4.3 Tundish
The tundish should be vertical, located in the same
space as the unvented hot water storage system and be
fitted as close as possible to, and lower than, the safety
device, with no more than 600mm of pipe between the
valve outlet and the tundish (see Figure 2).
Where discharge may not be apparent, e.g. in dwellings
occupied by people with impaired vision or mobility,
consideration should be given to the installation of a
suitable safety device to warn when discharge takes
place, e.g. electronically operated.
Note: To comply with the Water Supply (Water Fittings)
Regulations, the tundish should incorporate a suitable
air gap.
Note: It is important that the tundish is
positioned away from any electrical
components.
6.5 Immersion Heater
The water heater must be filled with water
before applying power to the appliance or
energizing the element. Failure to do so will
damage the element and void any guaran-
tee on the product.
To comply with Part L requirements it is necessary to
insulate the hot water pipework from the water heater
to the outlets, to reduce the energy requirements for
providing hot water. It is also recommended to insu-
late all other exposed pipework, such as the T&P to the
tundish, the coil flow and return and the cold water inlet
6.3.2 Pipe Insulation
The Edel Air Source Heat Pump Water Heater comes
with the immersion heater factory fitted and wired. The
immersion heater incorporates an independent non-self
resetting over temperature cut-out. Should this
operate, please investigate the cause of the cut out
before resetting (See Troubleshooting).
Where a manifold is used it should be sized to accept
and discharge the total discharge from all the D1
discharge pipes connected to it.
The discharge pipework from the expansion relief valve
must be installed constantly falling to an open point of
discharge. It is recommended to combine it with the
discharge of the temperature and pressure relief valve.
Note: The T&P valve is pre-sealed and if moved the
seal will be broken, should this occur, it will need to
be resealed with an appropriate sealant (Dimplex part
number R00836-1).
Installation
Dial to adjust
water temperature
Earth (green/yellow)
Live (brown)
Neutral (blue)
Figure 7: Cold water inlet group
!
The diameter of discharge pipe (D1) should not be less
than the nominal outlet size of the safety device, e.g.
temperature relief valve.
NOTE: The expansion vessel must be installed
to the side of the expansion relief valve
on the inlet group. To do this the blank-
ing plug must be removed and the ex-
pansion vessel connected, as shown in
Figure 5.
NOTE:The drain valve must be installed
lower than the appliance to ensure all
of the water is drained away should the
immersion heater need to be serviced.
Figure 8
: Wire diagram for Immersion heater
