Faulty Sea Cock

[rwakeham]

I have inherited a Jabsco electric toilet which I have never got to flush. It is discharging but not taking water in. I have tracked the fault to the sea cock. It is allowing air in when the pump is working. It is a standard Blake sea cock. Any idea what I need to do to it without filling the boat with water ?

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[Benbow]

Hard to understand how the seacock can let in air when the toilet sucks but not leak water.

Is it above the water line ??!

Is there an anti-syphon valve in the inlet pipe ? If so put a blob of blue-tack in its hole and see if that fixes it.




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[rwakeham]

I attached a length of pipe to the inlet pipe and found that:

1. With the sea cock open if I blew then air bubbled up outside the boat. So I knew that there were no blockages. If I sucked then air appeared to leak into the tubes.

2. With the sea cock closed I can't blow or suck anything in.

I can't see an anti-syphon valve anywhere but guess I need to have a closer look

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[Dipper]

If you can’t follow your inlet pipework from the sea cock to the toilet, you may find you have a ‘Quiet flush’ version which has a remotely mounted flush pump somewhere else on the boat. This could be faulty.

If you can follow your inlet pipework directly to the toilet, ignore this post!


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[Trevethan]

Can't see how the seacock itself could let air in and still maintain watertightness, unless its somehow above the waterline. On my boat the inlet is well below the wl, but the outlet is just at the surface so were I to swap the connection I'd have a similar problem. Is the inlet a long way down below the WL?

I think that an antisyphone valve even if open is not large enough to totally destroy the suction of a decent pump so some water should come through regardless. Feel around the top of the loop and close any holes with your fingertips and give it another go.

If that fails, its could point to a problem with the heads itself -- damaged impellor on the inlet side perhaps.

They are not designed to run try so the vanes might have been stripped off?

Try running a hose from the inlet on the macerator into a bucket and giving that a go. if it sucks then it must be problem with the pipework.


Hope helps,

Nick

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[rwakeham]

I agree - there appears to be no way that the sea cock can be watertight but not airtight. But how do I find where the air is leaking in ? The entire exterior side of the sea cock is below the water line. I guess the best thing to do would be to replace all piping from the outlet of the inlet sea cock to the toilet and try again ? I was wondering is the grease packing within the sea cock has in some way been stripped out ?

The heads themselves are working fine - I have tested this by taking a pipe from the toilet to a bucket of water. It will lift water from the bucket - even if there is air in the pipe.

By the way thanks all for you help in all of this - if nothing else it is assuring me of my own sanity.

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[Trevethan]

You must have a hole in the hose then. As you say swap it out and try again -- Try taking your hose that went to bucket and attaching to the seacock -- see if that works.



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