Cold Water Supply - andrews MAXXflo EVO CWH 150/302 Installation And Maintenance Manual

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.
CAUTION
Do not apply excessive torque to these nipples when making connections. The use of an
appropriate drinking water pipe sealing compound is recommended.
pipework is not recommended due to issues such as galvanic attack.
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 connect-
ed to an open vent supply provided the minimum supply pressure of 0.8 bar are maintained at all times.
CAUTION
This heater is factory fi tted with temperature and pressure relief valves. An unvented system must
be fi tted by an approved installer. Avoid water stagnation : If this new installation is not to be used
immediately, it should drained down
4.3.3 WATER QUALITY AND TREATMENT
In order to ensure the long service life of this appliance and all connected pipe work, a sample of drinking water
should be analysed before installation and compared against the following table:
If water sample readings are outside the limits given above, corrective action should be taken. For example, the
installation of a base exchange water treatment in areas of hard water.
CAUTION
When installing Andrews Water Heaters in hard water areas we would recommend that a water
treatment specialist is consulted.
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.
Installation
Hardness < 150ppm (10.6 Clark degrees)
Acidity 6.0pH to 8.5pH
22
The use of galvanised
MAXXfl o EVO 150/302