Ver 2_ES_EN_FR_IT_PT
11
fig 2.- Models NOFER SBxxxN/SB075S
3.- CONNECTION TO THE WATER SUPPLY.
The water heater may be connected to a closed-circuit pressure system which enables several points of
use. For safety reasons the supply pipe must be fitted with a return safety valve or alternatively, a valve of the
safety class that prevents the pressure in the tank from exceeding the nominal pressure by more than 0.1 MPa.
The heating of water in the heater causes the pressure in the tank to increase to the level set by the safety valve.
As the water cannot return to the water supply system, this can result in the dripping from the outlet of the safety
valve. The drip can be piped to the drain by installing a catching unit just below the safety valve. The drain
installed below the safety valve outlet must be piped down vertically and located in the environment that is free
from the onset of freezing conditions. In case the existing plumbing does not enable you to pipe the dripping
water from the return safety valve into the drain, you can avoid the dripping by installing a 3-litre expansion tank
on the inlet water pipe of the boiler. You should ensure that the return safety valve is functioning properly by
checking it on a regular basis i.e. every 14 days. To check the valve, you should open the outlet of the return
safety valve by turning the. The valve is operating properly if the water comes out of the nozzle when the outlet is
open.
F
C
Fig-3 Hydraulic installation
Legend:
1- Return safety valve
6- Checking fitting
2- Checking valve connection
7- Funnel with outlet connection
3- Non-return valve
4- Pressure reduction valve
F - Cold water
5- Closing valve
C - Hot water
Putting into service:
Before connect hydraulically the water heater to water network lets the water flow some to time to remove
all dirty which could damage the safety valve and block the diffuser.
To fill the water heater properly leave a hot water tap open to drain the water heater tank and only close it
when water comes out fluently. When water become hot after the necessary time tight again all connections to
assure a correct water sealing.
If the water network pressure is higher than the nominal pressure of the water heater, it is compulsory to
install special valve to reduce the water inlet pressure between 2 and 3 bar.
