We have had a few leaks from the domestic water system on our bavaria 34. The one that has happened on several occasions is when the shower on the transom has been used. The tap gets left switched on as the water only flows when the button is held down on the back of the shower head. When the head is pushed into its housing the button is just depressed enough to allow a slow trickle of water to leak back into the boat but not enough to activate the pump on sufficient occasion to draw attention to the problem. It doesn’t take long to collect a bucket or two in the bilge.
A more recent leak first showed itself when the pump started to get louder than normal and run on for a long time after the tap was closed. This turned out to be a broken filter body on the inlet side of the pump. The filter is only made of clear plastic and is not really up to the job. It breaks on the lugs used to lock the filter chamber so it can be taken apart for cleaning. We managed a temporary repair using Stainless steel mousing wire to hold both parts together. I have photographs but not a clue how to attach them to this article. (can Email if you want them). We will get a spare but the temporary repair is stronger than the original, just more difficult to clean.