Tanami has led me a merry chase trying to find the source of water in the bilge and particularly in the engine bay. The water was slightly salty so i assumed it was fresh water that had disolved the small amounts of salt lying in the bilge.
All the problems were intemittent. Sometimes there was a little, sometimes about a mug full. I evenually found a leak around the gas outlet at the stern. The silicon was leaking under the fitting that had not been installed tightly enough. I then reseated the staunchions.
The problem really showed itself when I had the boat out of the water for antifouling and left the batteries on charge overnight. I forgot that htis also heated the water. In the morning the boat had litres of water in the bilge in the morning. Now how can you get water in the bilge when the boat is not in the water?
Finally decided it must be the pressure relief valve on the calorifier but have still not seen it leak.
Finally found that if the motor is run when the water pressure pump is on the heating expands that water in the tank increases the the pressure and that relief valve leaks.
I have not actually seen where the leak is coming from(work in progress) but if I leave the pressure switch off and leave the tap over the sink open the hot water goes into the sink.

Can some one tell me the brand of fittings used on the water system.