Panasonic PAW-DHW270C1F Handbuch Seite 59

Overview
Water quality
The characteristics of the primary circuit water used from the time of commissioning, and for the working life
of the boilers, will conform to the following values:
• When filling a new installation, or when an installation has been completely emptied, the water used for
filling should conform to the following values: TH < 10°F.
• A substantial amount of raw water would lead to large deposits of scale, which can lead to overheating
and breakages. Make-up water should be the subject of close monitoring. The presence of a water meter is
obligatory: the total volume of all of the water introduced into the installation (filling + make-up water)
must not exceed three times the water capacity of the heating installation. In addition, the make-up water
must match the following setting: TH < 1°F.
If these instructions are not followed (sum of the filling and make-up water greater than three times the
water capacity of the heating installation), a full cleaning down (desludging and descaling) is necessary.
Protecting the installation against scaling
In order to protect the installation, additional precautions are necessary:
• When a water softener is present in the installation, a check of the equipment in conformity with the
manufacturer's recommendations is required in order to verify that it is not discharging into the network
water that is rich in chlorides: the chloride concentration should always be less than 50 mg/litre.
• When the network water does not present the desired qualities (e.g. very hard), a treatment is required.
This treatment should be performed on the filling water as well as any subsequent filling or make-up water.
Periodic monitoring of the water quality in conformity with the recommendations of the water treatment
supplier is necessary.
• To avoid a concentration of scale deposits (on the exchange surfaces, in particular), the commissioning of
the installation should be gradual, beginning with operation at minimum power and ensuring as a
minimum the nominal water flow rate in the installation before starting up the burner.
• During work on the installation, it should not be completely drained; only the required sections of the
circuit are to be drained.
Protecting the installation against corrosion
The phenomenon of corrosion, which can affect the materials used in boilers and other heating installation
equipment, is directly linked to the presence of oxygen in the heating water. The dissolved oxygen that
penetrates into the installation during the first filling reacts with the installation's materials and therefore
disappears quickly.
Without a renewal of oxygen via substantial additions of water, the installation remains undamaged.
However, it is important to follow the installation's dimensioning and operating rules, which aim to prevent
any continuous penetration of oxygen into the heating water. If this point is followed, the circuit water
presents the characteristics that are necessary to the durability of the installation: 8.2 < pH < 9.5 and
dissolved oxygen concentration < 0.1 mg/litre.
In the case where risks of oxygen intake exist, additional protective measures should be taken. We
recommend using the services of companies that specialise in water treatment issues; they will be able to
propose:
• The appropriate treatment for the installation's characteristics.
• A monitoring contract with a guarantee of results.
In the case of an installation with water that is in contact with heterogeneous materials, for example, with the
presence of copper and aluminium, an appropriate treatment is recommended to ensure the installation's
durability.
Installation Use Maintenance Warranty
EN
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