Jabsco Toilet

[pvb]

I'll check the instructions ... never was a manual reading type. thanks for the tip.

Good idea! Every week or so, people wrongly post on here about how rubbish they think Jabsco toilets are. The truth is, properly installed and maintained, they are virtually trouble-free. Which is why they are so widely used.

 

[BrianH]

If the bowl is filling up with seawater to sea level coming in from the heads outlet it must be syphoning back. I can't think of any other explanation. You need a loop with an anti-syphon valve. Any other solution, other than closing the outlet sea cock, will inevitably be hit and miss.

Richard

But syphoning implies an inverted U to prevent back flow that, if no air enters will syphon back. I have no inverted U, just a straight downward pipe from pump base to sea cock.

PVB has alerted me to a possible HR installation error - who'd a thunk it? If so, I've lived with two wrong installations from two respected boat builders for 34 years.

 

[RichardS]

But syphoning implies an inverted U to prevent back flow that, if no air enters will syphon back. I have no inverted U, just a straight downward pipe from pump base to sea cock.

PVB has alerted me to a possible HR installation error - who'd a thunk it? If so, I've lived with two wrong installations from two respected boat builders for 34 years.

I see what you mean. Not so much syphoning as water staying in the discharge pipe at it's own level. I'm surprised that the boat could have been built like that or even that the toilet flushed properly when the sea level would be constantly trying to push the effluent back into the bowl!

Richard

 

[Stork_III]

But syphoning implies an inverted U to prevent back flow that, if no air enters will syphon back. I have no inverted U, just a straight downward pipe from pump base to sea cock.

PVB has alerted me to a possible HR installation error - who'd a thunk it? If so, I've lived with two wrong installations from two respected boat builders for 34 years.

Both HRs I have owned have had a large loop up to deck level, in the locker, in the bowl to seacock line, with vented loop. Perhaps your was altered by a previous owner?

 

[BrianH]

Both HRs I have owned have had a large loop up to deck level, in the locker, in the bowl to seacock line, with vented loop. Perhaps your was altered by a previous owner?

Possible but unlikely, after all, there's space in the locker for a loop but everything looks original with no cut-outs where a tube would pass. And if PVB had a similar design error ...? Perhaps yours were later builds (post early 1980s) after they found out they were wrong?

The 1980 Trapper 500 with an identical configuration and also no loop, I bought new. It had exactly the same problem, so it wasn't just HR.

 

[KellysEye]

>Assuming it's a manual one that didn't do it beforehand, probably the joker or bottom flapper valve not sealing properly. Get a service kit and rebuild the pump (you get all the other wearing parts too) and this will prob solve it. This fault is not uncommon.

Agree. Out of interest the joker valve is a choker valve but that was patented hence the silly name.