380 S2: Water pump and accumulator

[Trevor Doble]

My accumulator blew a diaphragm, so I replaced the accumulator with a like for like. Now I have a couple of minor issue, and the more i Google them, the more wildly the responses vary.

First issue is that the pump is coming on from time to time (maybe two - three times a day)when no water is running. I assumed a leak, but can't find anything obvious - when I spoke to a Jabsco supplier he said it is not uncommon for the accumulator to come on intermittently - anyone else have this experience. In terms of the accumulator pressure, I have had advide varying from 8psi to 45psi! The pump cuts in at 10psi and out at 25psi. Any advice on that would be appreciated.

The second issue is that I found some fresh water in my port bilge. When I traced it back, it seems to be coming from the hot water system discharge pipe. Apparently this is used to empty the tank for winterising (not big issue in Cairns!). This seems to have happened since I replace the accumulator, so not sure if a coincidence of=r maybe something to do with the accumulator pressure.

Again, would appreciate any advice.

Thanks
Trevor

[Ballsnall]

The only reason your pump is cycling is due to a pressure reduction ie you have a leak, your jabsco supplier must have been a 15 year old kid to make a statement.like that.

Accumulator pressure should be set to a max of 70% of cut out pressure but as long as it it above the cut in pressure it will function just fine.

[Ballsnall]

Originally Posted by Trevor Doble

The pump cuts in at 10psi and out at 25psi.

To be specific,
I would set the accumulator pressure at 15 psi.

[Trevor Doble]

Originally Posted by Ballsnall

To be specific,
I would set the accumulator pressure at 15 psi.

Thanks mate, appreciate the advice. I have tracked down a leak, the hot water system has a release valve which is "shut" but is letting a bit of water through. Hopefully I can source a new valve and problem solved.

I'll pump the accumulator up to 15 and see how that goes.

[Huggi21]

Hi Had the same issue turned out to be the relay behind the pump not switching off , a pig to get to by the way on a 39 not sure on a 38

[leecea]

I have a Kumma water heater and the instructions say that the tank is designed to have an air gap at the top to allow for expansion of water when heated. It goes on to say that if the pressure release valve is letting water out it could be that the air gap has been lost and they recommend a drain/refill procedure to fix it.

[Trevor Doble]

Thanks for the feedback. I ended up putting a pressure gauge in my water line to try to see what was happening. Turns out the high pressure cut-off on my water pump was not working, it was supposed to cut off at 25psi but was exceeding the 60psi on my gauge. This had caused the accumulator diaphragm to split, and was also causing the hot water pressure release valve to let go - probably lucky it did work properly!

So... replaced the water pump and the whole system seems to be working exactly as it should. Having the gauge in the line now should help if we have any future fresh water issues.

[Bowdrie]

Originally Posted by Trevor Doble

Having the gauge in the line now should help if we have any future fresh water issues.

You are quite right.
I remote mounted a gage with a Schrader valve in an easy to see/use location.
A highly recommended set-up for any boat.