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Maintenance
2017/11
• Remove and clean the backwater preventer <25>. To do do, unscrew screws <1> and <2>
and push out the backwater preventer <25> from the side
• t the backwater preventer <25> again. Make sure that the
ventilation device <25A> is in a vertical position as shown
• Close the cover of the service opening <30>
• Carry out a functional check (see 3.7.2)
Ill. [21]
25A
25
Ill. [22]