Holding tank pump problems

[vyv_cox]

I did not realise that you have no upwards options, so going downwards seems to be the way. But I don't follow your 'sump below and before the joker valve' statement. The idea is to have some head of water above and after the valve to keep the lips closed.

 

[Chris_Robb]

I did not realise that you have no upwards options, so going downwards seems to be the way. But I don't follow your 'sump below and before the joker valve' statement. The idea is to have some head of water above and after the valve to keep the lips closed.

Yes - the top of the tank is at bunk level.

From the tank pump out point, I would insert a right angle bend, and flex pipe going straight down to the hull, bending upwards again to the pump intake about 8 inches up from the hull. Above the pump, flex pipe would go up to bunk level and follow its old course through the bulkhead and down to the hull seacock.

This would I hope leave some liquid in the U bend (or sump) before the pump.

 

[MON46]

Chris
I was relieved to see your post
these are the worst holding tank pumps I have ever come across.
The Joker valve is useless for holding tanks, the particles get stuck in the valve keeping it open and rendering the pump useless.
How Jabsco can continue to sell them beats me
It fails more than 50% of the time and ruins my sailing.
Lopoking for an alternative
Paul

Since I installed my holding tanks in 2010, I have had nothing but problems with the pump out system, which is a Jabsco tyoe diapragm pump with jocker valves. I am now onto my third pump, as none of the pumps have ever managed more than a weeks pumping without stripping down cleaning and rebuilding- not a job you want to do every week!

So first likely problem from Jabsco - jockers done up too tight. Tried all pressures - makes no difference.

When the pump fails to prime (DIp tube of approx 500mm into tank bottom.) I take it to peices and the jocker valves are not tightly sealed but slightly gaping. The effect at the suction end is to get a suck puff suck puff situation, which should of course not happen.as the jokes are just not sealing (I have tried many new ones.)

So what should I now fit. The Jabsco macerator has a max priming head of 600mm. It would fit in the area with some new piping as it discharges into a smaller bore.

I am not happy with Jabsco at all as they have been extremely unhelpful apart from new pumps which dont work!

 

[t21]

Hm, loads of useful answers here. In the not-so-useful department, I can tell you it is very good fun to do a bit of bogfixing with a Mars Bar, munch a bit of it and then smear the chewd bits over your face before emerging from the bilge/bog complaing to the crew that "Nope, it still won't work" and watch their faces. Excellent.

 

[MON46]

we have to try to keep our sense of humour

 

[Chris_Robb]

Chris
I was relieved to see your post
these are the worst holding tank pumps I have ever come across.
The Joker valve is useless for holding tanks, the particles get stuck in the valve keeping it open and rendering the pump useless.
How Jabsco can continue to sell them beats me
It fails more than 50% of the time and ruins my sailing.
Lopoking for an alternative
Paul

Despite jabsco saying these pumps can be installed horizontally. No they can not!

However now that I have installed mine vertically it no longer has a priming problem and worked faultlessly last year. The pumps themselves are much more robust than a macerator.
If only Jabsco would stop giving the wrong instructions they would probably find people would love the pump when installed vertically.