Installation guide

SECTION XX • XXXXXXXXX
10
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 water heaters and the higher the
temperature and volume of water used, the more
problematic the scale build-up can be. Water treatment
is normally recommended when the hardness reaches
100 – 150ppm (7 – 10 degrees Clark) and above. This
problem can be minimised by reducing the water
temperature in the heater and by fitting suitable water
pre-treatment equipment. It is for this reason we strongly
recommend water pre-treatment is fitted. A base-
exchange type of softener is strongly recommended
for a reliable solution to hard water.
WATER CONNECTIONS
An unvented system must be fitted by an
approved installer.
The pressure reducing valve C1 will regulate the mains
water pressure at 3.5 bar (provided there is sufficient
mains water pressure available). The maximum test
pressure should be 8 bar. The expansion vessel C3
supplied is suitable for the stored volume of the heater
and a comparative pipe work system. The temperature
and pressure relief valve(s) are factory fitted. FOR
SYSTEMS WITH LARGER PIPE VOLUMES OR
ADDITIONAL STORAGE, EXPANSION VESSELS
WITH MORE CAPACITY ARE AVAILABLE.
We do not recommend the use of galvanised pipework
due to issues such as galvanic attack (British Standard
BS6644). The MAXXflo has a number of copper and
brass components.
The cold water connection and the hot water connection
can be found on the top of the appliance, see Fig 1A and
1B. An extra connection is available for the benefit of a
circulation line. Please note that a stop valve should be
fitted in the circulation line.
The MAXXflo range of storage water heaters are designed
to work from a mains fed unvented system. An unvented
kit to regulate the cold feed is supplied with each heater
and should be installed as Fig. 1, 1a and 1b plus
drawings on pages 5, 6 and 7.
The temperature and pressure relief valves are supplied
factory fitted for external connection to a tundish
(supplied) and suitable drain. The MAXXflo can also
operate on vented systems providing the minimum water
pressure is one bar.
SECTION 3 • INSTALLATION
10
Expansion Vessel
Fig 1