andrews MAXXflo EVO CWH 30/201, Руководство по установке и обслуживанию

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Installation 22 MAXXfl o EVO
4.3 COLD WATER SUPPLY
4.3.1 CONNECTIONS
The cold water inlet and hot water outlet connection nipples are identifi ed on the top of the heater. Connect the
cold water feed and hot water outlet to these nipples with union adaptors for ease of servicing.
Fit a check valve and isolator in the cold water supply before the inlet to the water heater
Do not apply excessive torque to these nipples when making connections. The use of an
appropriate drinking water pipe sealing compound is recommended.
4.3.2 SYSTEM
The MAXXfl o EVO range of storage water heaters are designed to operate from a mains fed unvented water
supply. An unvented system kit is available from Andrews Water Heaters. However, the heater may be con-
nected to an open vent supply provided minimum supply pressures are satisfi ed.
When connected to a sealed or open vent water system a minimum water pressure of 0.8
bar must be maintained at all times.
This heater is factory fi tted with temperature and pressure relief valves. An unvented system must be fi tted by
an approved installer.
The use of galvanised pipework is not recommended due to issues such as galvanic attack.
4.3.3 WATER QUALITY AND TREATMENT
When installing Andrews Water Heaters in hard water areas we would recommend that a
water treatment specialist is consulted
In hard water areas scale formation can occur in all hot water systems and the higher the volume and hotter the
water used, the greater the scale build-up can be. Water treatment is usually recommended when the hardness
levels measures greater than 150 ppm (7-10 degrees Clark). For this reason, base exchange water treatment is
strongly recommended in hard water areas.
4.3.4 DE-STRATIFICATION PUMP
By virtue of its design, an internal DHW tank de-stratifi cation pump is not required.
4.3.5 ANTI-VACUUM VALVE
An Anti-vacuum valve must be fi tted to prevent a vacuum forming in installations where there is the potential of
the draw off rate exceeding the rate of fl ow to the inlet; this can occur in properties with multiple outlets below
the base of the hot water heater. The valve contains a check cartridge which under normal conditions is held
closed by the system pressure. When a vacuum condition exists, the suction will cause the check cartridge to
open and air to fl ow through, equalising the pressure within the hot water heater. The capacity of an anti-vacu-
um valve should be equal to or greater than the rate of the vacuum formation in the vessel being protected. An
Anti-vacuum valve kit (part number 7709364) is available for the MAXXfl o EVO that is capable of up to 3 litres/
sec @ 500mbar.