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Pump out problems - New Boat

Took ownership of our shiny new boat last year on December 16, and been living on it since. I have been using Silky RX holding tank treatment from the word go. Pump outs haven't been a problem until recently. The last three times, when I have been pumping out, the pump out pump at the marina has broken. A share pin has snapped. One fixed I can continue pumping out with no probems, however the next time I need to pump out it breaks again. Has now happened three times in a row. Other boaters don't seem to have a problem. I can't find any blockages that I can think of. I am to scared to go pump out again.

Asked by: Andre Skarzynski  | 3.32pm, Monday 13 March

WW says:

It could be possible that there is an unseen blockage in the tank or the pipework. Very occasionally, aome types of hoses used to make the tank-to-fitting connections delimainate internally, which can then collapse when under reduced pressure during emptying. Squeezing the pipe gently along its length may show if there are any soft spots which are unlike the rest of the pipe, but only a removal and full inspection can show this.
Another possibility is there is something in the tank which is blocking the draw-off standpipe (assuming a top-fitted suction pipe in the tank. This is fairly easy to check, if rather unpleasant (face mask, gloves, safety goggles and a strong stomach recommended!).
You might also want to check the air inlet line is clear of obstructions as if this blocks, the pressure can drop too low inside the tank- ideally the vent line should be at least a 1.5 inch (35mm) non-collapsing hose connected to the external air breather- and preferably the same diameter as the suction hose.
I may be worth trying a different pumpout machine at a different yard, just in case you have been unlucky. Otherwise you might need to get the boatbuilder to have a look- if it's underperforming and it's a new boat; it would be covered by the warranty. I wouldn't normally expect a major issue with the holding tank on an early-new boat. It may be that there is a fault in the installation.

Mark Langley  | 5.58PM, Monday 13 March

I agree with Mark, it sounds likely that there is something floating around in the tank that causes a blockage which overloads the suction pump breaking the shear pin.
It is important to only put conventional toilet paper (and the remains of what has been eaten) into a boat toilet. Anything else that people often put down the toilet should go into the bin. Little scented bags are available for tampons etc.

Rupert Smedley  | 9.42PM, Monday 13 March

You didn't say it was a macerator toilet and are obviously clued up on boat toilets. Hope I didn't cause offence.
Look at the vent line, it might be badly run and squashed or kinked or blocked.

Rupert Smedley  | 11.18AM, Tuesday 14 March

I should point out I once had a boat engine fail at sea due to welding swarf floating around a diesel tank which blocked the fuel pick-up...! Its even easier for a boatbuilder when cutting holes to add the fitments to a holding tank (especially if its plastic) to let them drop into the tank- hoping they never cause issues...!

Mark Langley  | 3.11PM, Tuesday 14 March

Readers say:

Thank you for the suggestions Mark. I will try and investigate all the options. The pipes all come into the top of the tank. I will have to remove a panel from the wall to check the full length of the pipe going up to the pump out port. If I can't find anything I will approach the boat builder. Rupert, if there is an object floating in the rank, it would have had to come through the macerator, and that appears to still be working okay. My partner and I are very strict on what goes down the loo and have little bags, and everyone who comes on board are instructed. But I guess anything can happen! I only buy the appropriate toilet paper too. Alternatively, maybe the boat builder left something in the tank!

Andre Skarzynski  | 10.43PM, Monday 13 March

No offence taken Rupert :)

Andre Skarzynski  | 12.39PM, Tuesday 14 March

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