Ariston VELIS EVO, Assembly And Operation Instructions Manual, Page: 8 / 24

8 / EN
PR TEMPERATURE
RELIEF VALVE
DRAIN
(not supplied)
HOT SUPPLY
15/22 mm
15 mm
COLD MAINS-IN
15/22 mm
TUNDISH
EXPANSION
RELIEF PIPE
EXPANSION
VASSEL
COMBINATION
VASSEL
Do not fi t any stop cocks or isolating valves within the distance required for expansion. If a pressure re-
ducing valve is needed, due to a mains pressure of over 3.5 bar, an expansion control kit must be fi tted
regardless of expansion pipework installed. The expansion distances quoted are for 15mm pipes and
can be approximately halved for 22mm pipes.
The appliance must not be supplied with water of hardness less than 12°F, not with especially hard water
(greater than 25°F); we recommend installing a water softener, properly calibrated and controlled - do
not allow the residual hardness to fall below 15°F.
The appliance is covered under the Building Regulations and therefore it is not possible to accommo-
date the expansion water within the system pipe work and consequently a set of expansion controls
must be installed.
Note: The discharge from relief valves must be made in a safe and conspicuous manner.
Please note that in all cases the dielectric junctions must be connected to the heater before any
other connection is made (these prevent an electrolytic reaction).