Viessmann M22, Operating And Service Instructions

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11
Protecting the heating water from oxygen ingress
■ Prevent continuous oxygen ingress and the entry of
airborne oxygen into the system during operation.
■ Apply technical rules, specifically VDI Guideline
2035-2.
■ Ensure that the heating system is designed correctly
(dimensions, system pressure).
■ Operate the heating system in line with regulations.
■ Equip sealed unvented systems with a diaphragm
expansion vessel, for example.
Recommendation for diaphragm expansion vessel
Check the pre-charge pressure during the annual serv-
ice at the latest.
Pressure maintaining systems and corrosion
"General engineering information" chapter in the
technical guide
Operate the system with positive pressure
■ In the entire boiler system
■ On the pump suction side
■ In every system operating state
Additional protection against oxygen ingress
■ Add an oxygen binder (excess of 5 - 10 mg
Na
2
SO
3
/l).
■ Adjust the pH value of the heating water to 8.2 - 9.5.
Use of aluminium components
Bear in mind that different conditions may apply.
Corrosion protection with chemicals:
Obtain a safety declaration from the chemical manu-
facturer regarding the interaction of the chemicals with
the materials used in the steam boiler, the hot water
boiler and the other components of the heating sys-
tem.
Recommendation
Consult the relevant contractor regarding water treat-
ment.
Detailed information
VDI Guideline 2035-2 and EN 14868
Water quality
Standard values for water quality
(cont.)
6152553
Service