Water Quality - Ygnis VARJET Serie Manual Tecnico

Exhaust gas temperature measured at the boiler smoke box (on Varjet, this temperature shall be
measured at the inspected hatches placed either side of the smoke box on the heater before the
condenser)

4.2 Water quality

The following rules apply once the boiler is put into service and remain valid until the end of life of the
product.
Preparing the water system before putting the boiler into service
For any installation (new or renovation), the water system pipes must be thoroughly cleaned. The purpose
of this initial cleaning is to eliminate germs and residue that can cause deposits to form.
In new installations in particular, residue from grease, oxidised metal, and even copper microdeposits
must be removed.
In renovated installations, cleaning should focus on removing sludge and the products of corrosion
formed when the unit was last in operation.
There are two types of methods for cleaning and removing sludge: a high intensity approach that takes a
few hours and a slower, more gradual approach that takes several weeks. This first type of cleaning must
be done before connecting the new boiler, and with the second type, a filter should be installed on the
back of the boiler to capture loosened deposits.
The cleaning performed prior to installation improves performance, reduces energy consumption,
and resists scaling and corrosion on the unit. A professional (water treatment) should carry out
the cleaning.
Protecting the unit against scaling
Water naturally contains dissolved calcium ions and carbonates that cause scaling (calcium carbonate) to
form. To prevent excessive deposits, take precautions with regard to the water used to fill the unit: TH <
10°f
Water must be added during the life of the boiler. The new water adds scaling to the water system. The
amount of fill water plus the amount of make-up water added during the life of the unit should not
be more than three times the water capacity of the heating system. Also, the hardness of the make-
up water must be controlled. Make-up water: TH < 5 °f
Adding a large amount of untreated water always contributes a significant amount of scaling. To monitor
this and to detect problems, a system water meter must be installed.
Failure to comply with these guidelines (such that the fill water plus the make-up water is more than three
times the water capacity of the heating system) requires a full cleaning (to remove sludge and scaling) to
be performed.
Additional precautions are required for operation:

When the unit has a water softener, the equipment must be inspected on a regular basis in order
to ensure that it is not outputting chloride-rich water into the system. The concentration of
chlorides must always remain below 50 mg/l.

To prevent the build-up of calcium deposits (such as on exchange surfaces), the unit should be
brought into service slowly, starting by operating at a low power with high primary water flow.

When the tap water lacks the desired qualities, water treatment is required. The fill water must
be treated, and whenever new water is added, the make-up water must also be treated.

Installations with multiple boilers require all of the boilers to be brought up simultaneously at
minimal power. Doing this prevents the calcium in the water from depositing on the exchange
surfaces of the first boiler.

When working on the unit, avoid draining it completely; only the required parts of the system are
to be drained.
The rules listed above are designed to minimise scaling on the exchange surfaces and thus to increase
the life of the boilers.
1NO0P0007-D
Varjet 1 - 14
Remove the screw and the joint
to take the measure of the
smoked temperatures and CO2
Trapdoor of visit
1NO0P0002_F4
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1NO0P0002_F3
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