Jabsco Accumulator Tank

[paulypaul]

Hi,
We have got ourselves a '75 Broom 30 and are in the process of carrying out remedial work that is required after a few years of neglect.

One of the problems is that we are unable to leave the water supply main switch on because there is an awfull thumping noise coupled with water pulsating out of a hull outlet. This mean that when you want to use a tap you have to go and switch the main supply switch on, then once you finish, it has to be switched off.

I initially thought it may be a leaking shower mixer fitting which I fixed, but it didnt make a difference. I then turned my attention to the pump which is fairly new and working well. There I found a Jabsco 1 litre accumulator tank fitted. The water from the hull outlet is coming from this.

The tank has a slow drip from the bottom T fitting and the top fitting, which according to the instructions should be hand tight, is incredibly tight and I can only get it to turn with pliers.

So, before I start messing with it, I was wondering if anyone could possibly give me some advise as to what the potential problem (apart from the dripping leak) could be and how to resolve it.

Many thanks, Paul

 

[tillergirl]

I am not sure how/why you have a hull outlet from your accumulator tank. Such a tank should just be in-line between the outlet of your pump and the distribution to taps etc. Certainly you should not have water leaking at all especially from the top which should only have air. That suggests the diaphram is stuffed promptoing the suggestion that you renew the accumulator. Current models have clip in connectors.

 

[paulypaul]

The leak is from the bottom T fitting where the hose and clips look like they have been poorly assembled. I may have described the set up incorrectly. I think the outlet to the hull comes from the calorifier which is in line after the accumulator tank.....I think (should have taken a photo cause I cant remember now)

 

[tillergirl]

The calorifier will have a pressure release valve to vent any excessive pressure as temperature builds up so some water from there is possible although it should not be pulsating out. That suggest the PRV is faulty - should be relatively easy to replace. The other issue that comes to my mind is whether the pump is switching off when it reaches max pressure. Depending on the pump there will be an auto switch there somewhere that triggers the pump on when pressure drops in the system (as you open a tap) or off as you turn off the tap and the system bulds up pressure. If the switch is not turning off the pump, the PRV could be operating correctly and venting excess pressure overboard.

 

[paulypaul]

I thought perhaps that the pump would have some sort of pressure switch on it rather like the water system on a caravan, but I cant find anything. Its a shureflow pump that simply has a fliter on the inlet side and a hose to the accumulator tank on the outlet. It seems to be a sealed unit so I'm stumped.

 

[PCUK]

The accumulator tank should also act as an expansion tank that allows the water to expand when heated without blowing the safety valve on the calorifier. Go back to the accumulator tank as I believe that is where the problem lies. If it has been leaking then it will be completely full of water and unable to accommodate the expanding water. They are not expensive, so fit a new one ensuring all joints are tight and you should have no further problems.

 

[nigelmercier]

The pump will have a pressure switch built into the base. There is an adjuster, but it is hard to see until you spot it.

 

[paulypaul]

Many thanks for all the advise,