7.3
Hydraulic connections
7.3.1
Preparing the water connections
1 Domestic hot water outlet (red collar)
2 Domestic cold water inlet (blue collar)
The components used for the connection to the cold water circuit must
comply with the prevailing standards and regulations in the country
concerned.
The water connections must comply with the corresponding standards and
local directives.
1. Remove the lower cover.
2. The domestic hot water circuits and cold water feed pipes must be
flushed before making any water connections to prevent metal
particles or other contaminants into the domestic hot water tank.
If flushing has to be done using an aggressive product, neutralise the
rinsing water before disposing of it in the waste water network.
7.3.2
Connecting the domestic hot water tank to the cold water
circuit
1. Install a pressure reducer if the mains pressure exceeds 80% of the
calibration of the safety valve or unit (e.g. 0.55 MPa (5.5 bar) for a
safety unit calibrated to 0.7 MPa (7 bar)).
Caution
Install the pressure reducer upstream of the appliance and
downstream of the water meter in such a way as to ensure the
same pressure in all of the system's pipes.
2. Install a non-return valve between the safety unit and the pressure
reducer to prevent the backflow of domestic hot water into the
domestic cold water circuit.
3. Install a water drain in the boiler room and a funnel-siphon for the
safety unit.
4. Incorporate a sealed safety valve calibrated to 0.7 MPa (7 bar) (not
provided) on the domestic cold water inlet, close to the tank, in a
position which is easy to reach, to protect the domestic hot water tank
from pressure surges.
Caution
There must be no cut-off devices between the safety valve or unit
and the domestic hot water tank.
5. To avoid restricting the flow of water in the event of overpressure:
the safety unit discharge pipe must be kept in the open, in a frost-
free environment, and have a continuous, downward gradient;
the diameter of the safety unit and its connection to the tank must
be at least equal to the diameter of the domestic cold water inlet on
the tank.
6. Make the connection to the domestic cold water.
Fig.38
MW-2000399-2
1
2
1
7 Installation
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7689749 - v03 - 25112019
