Vaillant 06-5084 Instrucciones De Montaje página 15

Special precautions must be taken when the unit is
installed in any region where the water contains high
levels of lime!
Vaillant recommends you to take the following precautions in
addition to exchanging the secondary heat exchanger for water
containing high levels of lime:
G Cut jumper W 18 on circuit board no. 25 29 60
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