Giona Holding SWT 120 Serie Instrucciones Para La Instalación, El Uso Y El Mantenimiento página 9

UK
Description of diagram 2:

(A) Safety valve (not supplied)

(B) Emptying cock (not supplied)

(C) Drain pipe (not supplied)

(D) Expansion vessel (not supplied)

(E) Pressure reducer (not supplied)

(F) Non return valve (not supplied)

(G) Stop cock (not supplied)

(H) Pump (not supplied)

( I ) Boiler (not supplied)
It is compulsory to install a safety valve upstream of the boiler.
The pipe connection between the boiler and the safety valve must not be interrupted, in order to
prevent damage to the boiler due to overpressure.
While installing the safety valve, (fig. 2 pos. A) pay attention not to tamper with the valve or to
press it at end stroke. The valve has a nominal set value of 8 bar.
A dripping from the safety valve is normal during the heating phase; for this reason it is
advisable to connect it to a siphon drain.
If the mains pressure is near the valve set pressure, it is necessary to install an adequate
pressure reducer (Fig. 2 pos. E) as far from the appliance as possible.
In case a pressure reducer or a check valve is installed, an expansion tank with capacity no
less than 5% of the nominal capacity of each heating unit (Fig. 2 pos. D) must be installed.
Do not install any check valve between the safety valve and the expansion vessel.
It is nevertheless always recommended to install an expansion vessel with the above
mentioned characteristics in order to protect the appliance and the piping network.
Inflate the membrane chamber of the expansion vessel according to the manufacturer
instructions.
Before connecting the unit it is necessary to fill it completely in the following way:

open the inlet cock

open a hot water tap (e.g. bath, sink, etc.) to allow the discharge of air inside; the
appliance is full when water flows freely from the hot water taps;

check for any leaks in the various plumbing connections;
In the presence of water with a hardness value >20°TH (where 1°TH=degree French=10mg
CaCo3/l) a water softener must be installed to prevent an excess of lime scale.
Please note that some water softener are comparable to non return valves and therefore their
installation requires also the installation of an adequate expansion vessel (see fig. 2).
The appliance is designed to be connected to a re-circulation piping: (Z) this piping must be
insulated.
Discharge junction (E) if not used, close it with a watertight plug.
Inlet and outlet piping must be connected to the designed positions of the boiler.
8