strada Aquatherm STA140UC, Technical Manual

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28/03/19
5
Water Treatment
In accordance with the Building Regulations L1A: New Dwellings/ L1B: Existing
Dwellings, the requirements set out in the Domestic Building Services Compliance
Guide specify that “where the mains water hardness exceeds 200ppm provision should
be made to treat the feed water to water heaters and the hot water circuit of
combination boilers to reduce the rate of accumulation of lime scale”. In most instances
of this water condition, an inline Water Conditioner/Scale Inhibitor would be fitted to
the incoming mains.
The water quality shall be in accordance with European Council Directive 98/83/EC, or
revised version at the date of installation, and is not fed with water from a private
supply. Particular:

Chloride content: Max. 200 mg/l

Sulphate content: Max. 200 mg/l

Combination chloride/sulphate: Max. 300 mg/l (in total)
The tank is part of the primary system and, along with other parts of the primary circuit,
will require the application of a protective scale and corrosion inhibitor such as Fernox
to ensure adequate protection. This should avoid having corrosive material in the
primary system and remove any build-up of sludge which can reduce the performance
of the High Efficiency Heat Exchanger Coil.
The volumes and concentration of inhibitor required should be calculated in accordance
with the manufacturer’s instructions. Please ensure that the thermal store volume is
also included as well as the radiator and pipework volume.
If there are doubts regarding the quality of water being used to fill the tank, an inhibitor
should be added to the appliance when filling in line with the manufacturer’s
instructions for these products.
Please note that the primary water within the thermal store water is used as primary
storage and the domestic hot water is heated instantaneously by means of the High
Efficiency Heat Exchanger Coil. Therefore, treating the primary water will not have an
effect on the domestic hot water supply.