Holding Tank yuk

[Saguday]

I have a blocked holding tank, looking for advice and pr'aps a bit of sympathy.

Are there any holding tank cleaning/servicing specialists around on the Essex/Suffolk coasts? Do French Marine do this sort of thing?

The only pump-out facility I know is at Brightlingsea which may or may not clear out some of it but the sea outlet via a macerator pump doesn't seem to work at all (although the pump may no longer be working, we've only tried to use it once).

Any advice, knowledge or experience? Or is it a question of opening up the valves and giving it a good poke?

 

[Habebty]

Fill holding tank with 2:1 water bleach, leave for a week then go sailing in F7 or above, leave for a week, then pump out or sell boat.

 

[maby]

Bleach and water may clear it - if it does not, it will, at least, make the subsequent task of poking it through a lot less unpleasant! If it does not clear with chemicals, then get a set of cable mousing rods from a good electrical wholesaler - someone like CEF. They are like very thin drain rods - usually made up in 1m lengths and screw together to make up a 10m length. They will get round corners and should be strong enough to clear the blockage.

Once you have it clear, get into the habit of cleaning it out every few months - close the outlet valve and fill with fresh water and a good slug of holding tank fluid. Let it stand for several hours, then drain off.

 

[MoodySabre]

First job is to find out what is stopping it pumping out. Is the pump running? Is the outlet sea cock really open? Is it the dip pipe inside the tank that is blocked by solids?

If you have a deck pump out then some high pressure water down there might help. If you can easily take the outlet hose fitting off the tank then a blast down there. If it is the sea cock can you get to the outside and rod it?

The worst I get is a stuck gauge so you think it is full or empty. Withdraw it and hose it down in a bucket. Best not to upset he marina hose that peeps fill there tanks from :disgust:

 

[nigelm]

Wondering what has caused the blockage , poop alone shouldn't , I once had a baby wipe down my sea loo that caused me several hours of grief , needless to say it hasn't happened since , not a nice job anyway you have my sympathy.

 

[Saguday]

Thanks chaps. Whenever I've the raised the question of getting this seen to all the marine professionals I've talked to become very evasive for some reason.

Fill holding tank with 2:1 water bleach, leave for a week then go sailing in F7 or above, leave for a week, then pump out or sell boat.

Good start, will do. If not successful, however, ability to sell boat may be compromised by extant blocked holding tank.

Bleach and water may clear it - if it does not, it will, at least, make the subsequent task of poking it through a lot less unpleasant! If it does not clear with chemicals, then get a set of cable mousing rods from a good electrical wholesaler - someone like CEF. They are like very thin drain rods - usually made up in 1m lengths and screw together to make up a 10m length. They will get round corners and should be strong enough to clear the blockage.

I was thinking of something to poke it with after I've had a go with a conventional pump-out. This sounds like a good idea, although I'm not sure I'd want to handle them after I've pulled them out again...

Once you have it clear, get into the habit of cleaning it out every few months - close the outlet valve and fill with fresh water and a good slug of holding tank fluid. Let it stand for several hours, then drain off.

Always used to do this, always flushed and pumped with fresh water after each pump out. Inability to get to boat and do basic maintenance last couple of years has resulted in the blockage though. Once we're back to normal this should't be a problem again.

First job is to find out what is stopping it pumping out. Is the pump running? Is the outlet sea cock really open? Is it the dip pipe inside the tank that is blocked by solids?

We tried pumping well out at sea via the macerator, the pump ran fine initially and the satisfying aromas told us it was flushing out, but then it ceased with the pump running and no discharge. Tank gauges still showed it was not empty (and no reason to believe otherwise as not enough had come out). Checked all the diverters and seacocks and it otherwise seemed to be fine. Shut down pump for fear of burning out motor. Plan to check all this again though as part of Plan S.

If you have a deck pump out then some high pressure water down there might help. If you can easily take the outlet hose fitting off the tank then a blast down there.

Yes, deck pump out, that's the only way we've every pumped it out except for the one aborted but partially successful attempt out at sea. I did wonder about a jet wash down the schnozzle but have a morbid fear of the splash back. It's a good 2m from the deck pump-out cap to the holding tank entry as well.

If it is the sea cock can you get to the outside and rod it?

This is the stuff of nightmares, though... the answer is yes when hauled out but the holding tank is almost 210 litres and I think it's about 60-70% full still. The idea of standing anywhere near it poking it with a pointy stick fills me with horror.

The worst I get is a stuck gauge so you think it is full or empty. Withdraw it and hose it down in a bucket. Best not to upset he marina hose that peeps fill there tanks from :disgust:

Tank gauge seems to be working fine, I have no reason to believe the reading is not correct at the moment.

 

[PaulRainbow]

My first job would be to investigate the maserator pump. If that was running there's more than a good chance it would clear it.

Something to try might be removing the vent pipe from the through hull, connecting a hose to it (securely) and turning the tap on with nothing else open but the empty to sea, sea cock. Bit of pressure might shift things.

As others have said, a regular clean is a sound policy. When our tank is in use we regularly fill it with water and flush through a couple of times.

 

[Robin]

oVER here in the US the RV stores sell 'wands' that attach to a hose to poke in and spray around, maybe a motor caravan shop might have something similar?

 

[Saguday]

Wondering what has caused the blockage , poop alone shouldn't , I once had a baby wipe down my sea loo that caused me several hours of grief , needless to say it hasn't happened since , not a nice job anyway you have my sympathy.

My fear is that it's dried up a bit in there, at least near the pipework, hence the blockage. Some way of dissolving/re-liquefying the contents is a first step.

There has never been anything like a wipe or nappy or anything down the loo.

 

[Saguday]

My first job would be to investigate the maserator pump. If that was running there's more than a good chance it would clear it.

Something to try might be removing the vent pipe from the through hull, connecting a hose to it (securely) and turning the tap on with nothing else open but the empty to sea, sea cock. Bit of pressure might shift things.

As others have said, a regular clean is a sound policy. When our tank is in use we regularly fill it with water and flush through a couple of times.

Yes I will look again at the pump. If I'm confident the pump is ok then I can concentrate on encouraging the poo into a nice liquid enough state to run through it.

I'll look again at the pipework arrangements for the tank. I was peering around at the weekend and it all seems easy enough to get at but the fact that the access is all from under the floor in our cabin dissuades me from being too hung-ho and experimental.

 

[pvb]

It sounds like the stuff has settled out in the bottom of the tank and caused a blockage. OK, time for lateral thinking. If you can disconnect the tank vent, then apply vacuum to the pipe, that should suck seawater in through the macerator pump and agitate the contents in the bottom of the tank.

 

[Saguday]

oVER here in the US the RV stores sell 'wands' that attach to a hose to poke in and spray around, maybe a motor caravan shop might have something similar?

This is what I was thinking of, I was sure this sort of thing must exist. If I could poke a jet of water in from the deck pump-out point but steer it into the tank I'm sure I could loosen it up. I think there may be a load of internal baffles inside the tank though, not sure, which might stop me going all the way in.

I'll do a bit of googling

 

[Saguday]

It sounds like the stuff has settled out in the bottom of the tank and caused a blockage. OK, time for lateral thinking. If you can disconnect the tank vent, then apply vacuum to the pipe, that should suck seawater in through the macerator pump and agitate the contents in the bottom of the tank.

Also plausible.

What is the appropriate response when the contents unblock and rush up the hose and into the vacuum?

Job for a Henry Wet'n'Dry instead of the posh Dyson?

 

[pvb]

Also plausible.

What is the appropriate response when the contents unblock and rush up the hose and into the vacuum?

Job for a Henry Wet'n'Dry instead of the posh Dyson?

You said the tank's only 60-70% full. I'd have thought you could have unblocked it before the level reaches the vent pipe.

Rather than a vacuum cleaner, a manual pump might be better. Do you perhaps have a Pela pump?

 

[nigelm]

How about some elsan blue chemical stuff ? Used in porta loos to break up solids , might help ..

 

[MoodySabre]

I used a Pela pump to clear my sink drain - brilliant because it sucks and blows so frees any blockage. I reckon it's a good chance that it is the dip pipe that is blocked so if you can remove the tank fitting for the outlet pipe and use a Pela pump that might do it.

Man up Neil.

 

[pvb]

I reckon it's a good chance that it is the dip pipe that is blocked ...

But that wouldn't stop discharge through the macerator pump, would it?

 

[MoodySabre]

But that wouldn't stop discharge through the macerator pump, would it?

Yes - the dip pipe is on the outlet.

 

[pvb]

Yes - the dip pipe is on the outlet.

Doesn't that rather depend on the tank? The deck pump-out fitting would surely be the dip tube. The macerator pump will just be connected to the bottom of the tank.

 

[Sinbad1951]

If it's a macerator pump then it's most likely that the rubber impeller has dried out and chucked its blades or... There is a bit of floss or something caught around the two stainless choppers which do the macerating. Pull the pump apart. It's very straight forward and not as yucky as you imagine.
Meanwhile go to camping shop and get a large container of Elysian blue for the camper/motorhome toilets. A dollop of this in the tank will dissolve most things.
Finally once it's working, chuck the macerator away. The impeller will set you back £30 quid and won't last. Look at a 12v vacuum pump. No cutting blades or impeller..