Viessmann Vitocrossal 300 Service Instructions For Contractors page 142

Water quality requirements
(cont.)
Where chemicals are used as part of the
corrosion protection, we recommend
that the manufacturer of the chemicals
issues a certificate of suitability of the
additives with regard to the boiler mate-
rials and the materials of the other heat-
ing equipment components. We recom-
mend you refer questions regarding
water quality/treatment to an appropriate
specialist.
Further details can be found in VDI
Directive 2035-2 and EN 14868.
142