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7217402.01 - en
INSTRUCTIONS FOR FITTERS
Drain the water in the storage boiler as follows:
• close the water inlet tap;
• open a user tap;
• open the relative drain tap (Fig. 3-B);
• loosen the nut on the DHW outlet pipe at the bottom of the storage boiler.
24. DRAINING THE STORAGE BOILER
25. DHW EXPANSION VESSEL (AVAILABLE ON REQUEST)
Expansion vessel kit comprising:
- 1 stainless steel expansion vessel;
- 1 support for expansion vessel;
- 1 nipple G1/2”;
- 1 lock nut;
- 1 connection hose.
Connect the hose (supplied as an accessory in the expansion vessel kit) to the two connectors
A
and
B
as shown in figure
11.
For special areas, where the water is harder than 25 °F (1 °F = 10 mg calcium carbonate per litre of water), install a polypho-
sphate dispenser or an equivalent treatment system, compliant with current regulations.
The DHW expansion vessel should be mounted if:
• the pressure of the water supply or lifting system is such as to require the installation of a pressure reducer (pressure
higher than 4 bar)
• a non-return valve is fitted to the water supply line
• the water supply network is insufficient for the expansion of the water contained in the storage boiler and it is necessary
to use the DHW expansion vessel.
Tip
For the efficient operation of the expansion vessel, the pressure of the water supply must be lower than 4 bar. If it is not,
install a pressure reducer. Adjust the pressure reducer to obtain a water supply pressure less than 4 bar.
Figure 11