Well, I always say that this boating lark is a big learning curve.........
I previously posted about solving, so I thought, the problem of water in our cabin bilge, I fitted a wooden bung in a hole just above the waterline, that hole turned out to be the drain in the bottom corner of our gas locker. It rained and our cabin bilge had water in it again and our gas locker had quite a bit too. So out came the bung and the gas locker drained.
The cabin bilge needed a bit more attention, we sucked out all the water with our wet & dry vacuum, previously I'd noticed a 12v feed to the inspection hatch and assumed that it had at some time powered a bilge pump, but couldn't find a suitable drainhole for it, then I found a hole through the engine bulkhead, so I've now fitted an auto bilge pump so it will pump into the engine bilge where it can then be pumped out.
The engine seems to be running sweetly and the header is not overheating since I cleared the blockage in the calorifier.
I beefed up the raw water hoses and this seems to have cured our raw water problems, I checked the impellor and it was luckily undamaged by the intermittent water flow.