Heating engineer
Installation, use and maintenance manual – AY
21
3
3.2.7
System water quality
Responsibility of the user/operator/installer
The installer, operator and user must assure system
water quality (Table 3.2
p. 21). Failure to comply
with the manufacturer's guidelines may affect op-
eration, integrity and life of the appliance, voiding
the warranty.
3.2.7.1
System water characteristics
In order to avoid any scale or deposits on the pri-
mary exchanger, the water in the system must be
treated in accordance with the applicable stand-
ards. This treatment is absolutely essential in cases
where there are frequent episodes of water supply
or partial or total emptying of the system.
The filling and top-up water brings a certain amount of
calcium into the system. This is attached to the hot parts
including the heat exchanger, thus creating pressure
drops and thermal insulation on the active parts. This can
lead to damage.
If the filling and top-up water of the system is outside the
values indicated below, it must be softened and/or chem-
ically treated. Additives may also be added to keep the
calcium in solution. Hardness should be checked regularly
and recorded on the system logbook.
The choice of the type of treatment must be made accord-
ing to the characteristics of the water to be treated, the
type of plant and the limits of purity required.
Adhere to the chemical-physical parameters in Table
3.2
p. 21 and the regulations on water treatment for
residential and industrial heating systems.
Table 3.2
Chemical and physical parameters of water
Acidity
7 < pH < 8,5
Conductivity
< 400
μS/cm (at 25°C)
Chlorides
< 125
mg/l
Iron
< 0,5
mg/l
Copper
< 0,1
mg/l
3.2.7.2
Water topping up
The chemical-physical properties of the system's water
may alter over time, resulting in poor operation or exces-
sive topping up.
▶
Ensure there are no leaks in the installation.
▶
Periodically check the chemical-physical parameters
of the water, particularly in case of automatic topping
up.
Chemical conditioning and washing
Water treatment/conditioning or system washing
carried out carelessly may result in risks for the ap-
pliance, the system, the environment and health.
Contact specialised firms or professionals for water
treatment or system washing.
Check compatibility of treatment or washing prod-
ucts with operating conditions.
Do not use aggressive substances for stainless steel
or copper.
Do not leave washing residues.
3.3
FUEL GAS SUPPLY
3.3.1
Gas connection
▶
AY 35: 3/4" M
▶
AY 50: 3/4" M
▶
AY 100: 1" M
on the right, at the bottom, connection plate (Paragraph
▶
Install an anti-vibration connection between the ap-
pliance and the gas piping.
3.3.2
Mandatory shut-off valve
▶
Provide a gas shut-off valve (manual) on the gas sup-
ply line, next to the appliance, in a visible and easy ac-
cessible position, to exclude it when required.
▶
Perform connection in compliance with applicable
regulations.
3.3.3
Gas pipes sizing
The gas pipes must not cause excessive pressure drops
and, consequently, insufficient gas pressure for the
appliance.
3.3.4
Supply gas pressure
This appliance is equipped for a maximum gas
supply pressure of 50 mbar.
The appliance's gas supply pressure, both static and dy-
namic, must comply with Table 3.3
p. 21, with tolerance
± 15%.
Non compliant gas pressure (Table 3.3
may damage the appliance and be hazardous.
Table 3.3
Network gas pressure
Product
category
Country of destination
Gas supply pressure [mbar]
G20
G25
G25.1 (1)
G25.3 G2.350 (1) G27 (1)
G30
G31
II
2H3B/P
AL, BG, CY, CZ, DK, EE, FI, GR, HR, IT, LT, MK, NO, RO,
SE, SI, SK, TR
20
30
AT, CH
20
50
HU
25
30
The appliance gas supply pressure, both static and dynamic, must comply with the values in the Table, with a tolerance of ± 15%.
1
Gas not available for Caldaia 35 Tech, Caldaia 35 Tech ACS, Caldaria 35, AY 35.
