Its plumbing time .We have been having a few problems lately with our pressure relief valve (PRV) on our calorifier. Every time we used any water the PRV would operate and start emptying all of our water out of the water tank and overboard into the canal. We found out that our water pump starts operating when the pressure drops below at 1.4 bar and switches off when it reaches a maximum pressure of 2.4 bar. Also our flojet quad 4404 water pump that we have does not require an expansion tank as there is a built in bypass valve in the pump. The PRV we have at the moment is a 2.5 bar one ,so it leaves only 0.1 bar . After checking what pressure the pipework and fittings could take we have decided to fit a 3 bar PRV.
There, job done and no leaks. After heating up the hot water we tested it and it worked a treat. We are now waiting for the next thing to go wrong as it always seems there is a problem somewhere waiting to happen on a boat.