Caution
Do not connect the domestic hot water connection directly to cop
per pipes in order to prevent galvanic couplings in iron/copper
(risk of corrosion). It is compulsory to fit the domestic hot water
connection with a dielectric union (provided).
Safety valve or safety unit
Caution
In accordance with the safety regulations, a safety unit calibrated
at 0.7 MPa (7 bar) must be fitted on the domestic cold water inlet
on the domestic hot water tank.
France: We recommend NF-marked hydraulic diaphragm safety units.
Safety valve: 0.7 MPa (7 bar).
Integrate the safety valve in the cold water circuit.
Install the safety valve close to the water heater in a place with easy ac
cess.
Sizing
The diameter of the safety unit and its connection to the water heater must
be at least equal to the diameter of the domestic cold water inlet on the
water heater.
There must be no cut-off devices between the safety valve or unit and
the water heater.
The discharge pipe in the safety valve or unit must not be blocked.
To prevent the flow of water being hindered or obstructed in the event of a
pressure surge:
The discharge pipe from the safety unit must have a continuous and suf
ficient gradient, and its cross section must be at least equal to the cross
section of the opening of the safety unit outlet (to prevent the flow of wa
ter being hindered if the pressure is too high).
The cross section of the discharge pipe from the safety unit must be at
least equal to the cross section of the opening on the safety unit outlet
Isolation valves
Hydraulically isolate the primary and domestic circuits with stop valves to
facilitate maintenance on the DHW tank. The valves make it possible to
carry out maintenance on the tank and its components without draining the
entire installation.
These valves are also used to isolate the tank when conducting a pressur
ised check on the tightness of the installation if the test pressure is greater
than the admissible operating pressure for the tank.
Caution
If the mains pipes are made of copper, fit a sleeve made of steel,
cast iron or any other insulating material between the tank's hot
water outlet and the pipes to prevent corrosion to the connection.
Connecting the domestic cold water
Connect to the cold water supply according to the hydraulic installation di
agram.
The components used for the connection to the cold water supply must
comply with the prevailing standards and regulations in the country con
cerned.
Install a water drain in the boiler room and a funnel-siphon for the safety
unit.
Fit a non-return valve to the domestic cold water circuit.
5 Installation
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