Waste Holding Tank Problem

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georgieboy

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I have a grey holding tank conected to a masarator pump .The pump has a run dry cut out switch .I cannot get it to empty the tank it runs for a few seconds then cuts out.I have rodded the waste pipe to ensure no blockage from the tank to the pump ,all clear.the outlet from the pump out through to the skin fitting is also clear.
I did get a big bubling noise from the tank with the pump running a bit longer .
I have changed the pump and the old one took apart and tested all ok.
I can only think that air from a fitting is stopping a vacuume forming but I have tightened all of the fittings and cannot see any seepage to point to a leak.
Any ideas please
 
I have the same occurence on Rafiki. I had the inspection lid off the tank a few weeks ago, expecting to find a lump of ****e blocking the entrance, but the pump picks up through 6 cavities, and no sign of blockage.

Therefore I am resigned to pressing the switch on and off, on till I can't hear anything spilling out the exhaust. To empty a full 40 gal tank takes about 15 mins, lying down in the midberth. Tough job to stay awake some times!
 
would it be possible to empty the tank from a waste disposal berth on this occasion and then fill partial with water.. give the macerator a go again after swirling the water around a bit through the inspection hole and repeat until working?

if the inspection hole allows, may even be possible to position the pooh hoover over the inlets to the macerator to see if it sucks anything out that may be causing the blockage?
 
Good thinking Gary. On mine, the merc will pump out, but a bit at a time. Will definitely check the vent for blockage though. Hadn't thought of this one.
 
the pump on my tank was unable to pump out any "stuff" cos the pick up pipe had fallen off the fitting.Replaced the missing bit that goes down into the depths and everything starting working again.
 
When I had problem with my previous boat someone told me to put a hose in the waste outlet where you pump it out, they said make up joining section and add a piece of hose and stuff it down as far as you can and turn it on. I did this and a few bubbles and gurgles and it came back to life.
 
oldgit said:
the pump on my tank was unable to pump out any "stuff" cos the pick up pipe had fallen off the fitting.Replaced the missing bit that goes down into the depths and everything starting working again.
Click to expand...

If the tank and pick-up pipe is alloy, corrosion can/will cause holes to develop in the pick-up (and the tank) and break the suction, not allowing the tank to ever empty totally.

Alloy and poo don't seem to mix very well.
 
Thanks guys

Interesting about breather carlton was not aware of one will now have a hunt.The tank is glass fiber built into the superstructure so no inspection cover /access.All the fittings are plastic with jubilee clips holding them on and the boat is only four years old so I think I can discount corrosion.Solentphil thanks good idea will try the hose through the waste as another option.As always with boats access to fittings etc makes diagnosis and fix difficult.
Appreciate your help
 
Bit involved, but if you block the breather pipe on the outside of the boat with a (well fixed) bung, can you smear the pump-out fittings and connectors at the tank with slightly diluted washing up liquid, and then slightly pressurise the tank by continuously flushing the toilet and look for bubbles indicating a leak?

Failing that, I believe that the pickup pipe inside the tank can come adrift inside the tank at the fitting, which breaks the pickup suction internally. The only way to solve this is to cut a hole in the top of the tank and fit an inspection hatch eg a whale tcl/4. Then you can get inside the tank and fix it.

Really not a pleasant job but the only way if no external leak is apparent.

Cheers
Jimmy
 
Last edited:
The pipe from the tank to the macerator pump does not have any water in it . Ours does the same. I took the pipe off and filled it with water and away it went again. Also removed inspection cover :( and filled tank. Ours is to do with the pipe emptying when tacking.
 
Ok, this isn't weird at all: here's a picture of the inside of my holding tank, the big white pipe is the macerator pick-up pipe, and you can see the joint I was referring to in my previous post. Enjoy!

a0fe6752.jpg


Cheers
Jimmy
 
Jimmy

Thanks for your ideas and particularly the picture.I had assumed the waste pipe was at the bottom of my tank streight out but looking at the picture it could be a t the top with a 90degree bend .I have had a lot of bubbling at stages coming from the tank but no waste out could it be then that the down pipe has been dissengaged so the reason for the bubbling does that make sence ?

I have contacted the boat builders to find out the configeration of the fittings.

ps tank part of the boat structure and no access !
 
georgieboy said:
ps tank part of the boat structure and no access !
Click to expand...

What boat is it? It would be extremely odd for a boat to be constructed in such a way that no access to the holding tank would ever be possible. I suspect that you or praps the builder is going to need to cut an access hatch in the tank.

Have you got a deck pump-out outlet?

Cheers
Jimmy
 
Jimmy

The boat is a sealine CS29 the tank is fibreglass and built in under the galley floor.There is no access. Worst case we would have to take up the floor and cut an inspection panel not good !
 
georgieboy said:
Jimmy

The boat is a sealine CS29 the tank is fibreglass and built in under the galley floor.There is no access. Worst case we would have to take up the floor and cut an inspection panel not good !
Click to expand...

You could do worse than start a new thread 'Sealine SC29 - holding tank problem' and see if there are any other owners on the forum who have needed to get at the holding tank. Sealine do sometimes make it very difficult to get at things, and so somebody might already have figured this one out.

Cheers
Jimmy
 
georgieboy said:
Sorry Jimmy yes have got a deck pump out outlet joins in a y fitting in bilge into pipe coming from waste tank
Click to expand...

What's connected to the other branch of the 'y' piece - not the macerator, is it? Pure guesswork here - but if it is, then the deck fitting would need to be properly airtight in order for the macerator to work. (But this would be an odd design choice, so I doubt it, somehow).

Cheers
Jimmy
 
jimmy_the_builder said:
You could do worse than start a new thread 'Sealine SC29 - holding tank problem' and see if there are any other owners on the forum who have needed to get at the holding tank. Sealine do sometimes make it very difficult to get at things, and so somebody might already have figured this one out.

Cheers
Jimmy
Click to expand...

... or you could try a pm to Harpsden or D3B, I believe they are or have been owners.

Cheers
Jimmy
 
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