Kranzle 122 Silent Operating Manual page 23

The pressure gauge shows full pressure although the gun has
been closed. The pressure switch valve switches constantly.
Possible cause no. 2: The non-return valve body is soiled or the O-
ring at the non-return body is defective.
There is no guarantee if the pump is damaged by
defective O-rings due to air induction or lack of water
(cavitation).
Proceeding:
Switch off machine and pull plug from
socket. Stop water supply. Unscrew pump
outlet.
Take out non-return valve body and check
for soiling or damage of the O-ring.
Replace O-rings in case of damage..
23