Author Topic: Waste water tank, how to get empty?  (Read 1698 times)

Gilster

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  • Boat Model: Cruiser 41
  • Boat Year: 2022
Waste water tank, how to get empty?
« on: October 11 2022, 16:11 »
My problem with my new Cruiser 41 is how to get the waste tank empty.

My dealer told me I just have to open the big valve going outside in the small wardrobe beyond the sink in the bathroom. But the display says always : level is (still) 75%.

And the tank is really filled to 75%.

Best regards and thank you in advance


tiger79

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Re: Waste water tank, how to get empty?
« Reply #1 on: October 11 2022, 16:50 »
Welcome to the forum!

The tank should empty by gravity when the exit seacock is opened. It's possible that the pipe or seacock is blocked.  If you leave the seacock open and motor around in choppy waters for a bit, it's possible that the blockage may clear itself.  Alternatively, you could get the tank contents sucked out through the deck fitting, rinsing the tank several times while doing this, and then you'll have less effluent to cope with when you physically unblock it.  This can be done with a flexible spiral drain clearing rod, from the outside of the exit seacock.  If you're somewhere warm enough to get in the water, you could try this yourself.  Otherwise, it's a nicer job if you get the boat lifted out first.  Alternatively, if you're built like a gynaecologist, you could try putting a flexible drain rod down the pipe from inside the tank, getting access through the inspection hatch.

I wouldn't recommend trying to remove the outlet hose from the exit seacock - this will result in effluent getting in to inaccessible bits of your bilges and you'll never get rid of the residual smell.

To avoid this happening in future, make it a rule that absolutely nothing goes in to the toilet unless it's passed through a human first!  No toilet paper, wet wipes, cotton balls, etc, these should all go into a nappy bag and be put out with the rubbish.


Petef

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  • Boat Model: Bavaria 34 Cruiser
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Re: Waste water tank, how to get empty?
« Reply #2 on: October 11 2022, 23:48 »
I concur with Tiger 79. We had the same problem with the tank registering 75% full. Unfortunately, that is just over the level to open the inspection hatch on our B34. I tried prodding from underneath the boat to no avail. I think the problem we had was that the tank hadn't been emptied possibly due to the  lock downs during 2020/2021. We bought the boat in April 2022. The tissue etc had set like concrete in the tank as it had dried out over the the 2 years, blocking the the exit via the sea cock. I had replaced the sea cock and the pipe to the holding tank whilst ashore. But once in the water we couldn't empty the tank. I poured 2 bottles of bleach down the pump out and left for a couple of days. Then to get some movement, I taped up the air vent and taped the Dinghy pump into the deck "pump out" ( bloody difficult to get air tight!) then used the dinghy pump to put some pressure into the tank. It moved some Stuff, but needed more, so I tried the pump in deflate mode (suck) and then blow. This seemed to allow some of the "fluid" to release, and another pump to pressure aided the exit of some "fluid" to go. Using a torch I could see that the level was below the inspection hatch (just!). I used a metal coat hangar with a small bend (like a hook) at the end via the inspection hatch to loosen the mass of solid tissue. Pulling out smal bits at a time and I mean small bits, knocking them off into a bucket. It took ages but eventually I could feel that I was moving larger lumps and then the tank started to empty. And this was evident when you looked over the side lol! I used the shower to to put fresh water through (but that wasn't enough) we thought we had it sorted and left the sea cock open, but a few days later the 75% alarm went off. So rinse and repeat. The second attempt at clearing the tank seems to have worked and we now operate a if its not gone through your body it doesn't go through the toilet policy. Whilst in a marina/port we use the facilities to do number 2's. Wee's are ok especially at night, but my wife puts the paper in a bag not the toilet.

hope this helps

elias

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Re: Waste water tank, how to get empty?
« Reply #3 on: October 12 2022, 11:22 »
Happened to me too ,took a suction cup , with the dinghy outside of the boat , is just below waterline , pump it sometimes and unstuck . I had a kilo of oxalic acid powder on board (I know is not the most efficient), closed the sea cock , i big pot of warm water and all the powder for 4 hours . All gone

kavok

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Re: Waste water tank, how to get empty?
« Reply #4 on: October 13 2022, 10:19 »
Holding tanks are always a problem on Bavaria
I use direct outlet.
0 problems, no smell and dirty job.
When I bought the boat I find the holding tanks very dirty and difficult to clean. I used chemical wc cleaner and water.

Sootydog

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Re: Waste water tank, how to get empty?
« Reply #5 on: October 15 2022, 11:58 »
I have used a dinghy pump on the outside whilst sat in the tender. Watch out though, when it clears it floods out down the pump pipe and i ended up with a few litres in the tender.  Not nice!
This season it didnt work. Pushed a drain snake up from the outside with very little effect. If the tank level is lower than the inspection hatch, i have found a suitably curved stick from the beach and used it to give a good poke around on the inner surface of the tank.  During our time away during covid, any fluid left in the tank had evaporated and left a surprisingly solid layer which was quite hard to shift.