Install the safety valve close to the water heater in a place with easy
access.
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
sufficient 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 water 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 water heater.
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 water heater when conducting a
pressurised check on the tightness of the installation if the test pressure is
greater than the admissible operating pressure for the water heater.
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
Make the connection to the cold water supply according to the hydraulic
installation diagram.
Install a water drain in the boiler room and a funnel-siphon for the safety
unit.
The components used for the connection to the domestic cold water
supply must comply with the prevailing standards and regulations in the
country concerned.
Pressure reducer
If the supply pressure exceeds 80% of the safety valve or unit calibration
(e.g.: 0.55 MPa/5.5 bar for a safety unit calibrated to 0.7 MPa/7 bar), a
pressure reducer must be located upstream of the appliance.
Install the pressure reducer downstream of the water meter in such a way
as to ensure the same pressure in all of the system's pipes.
6 Installation
32
ETWH
7629886 - v07 - 20072020
