Toilet doesn't pump out when Y valve set to holding tank

[eriksp]

As an alternative to opening the inspection port, do you have a pumpout deck fitting?

If you open the cap on this fitting and hear air rush out, that is an indication the problem may be with your venting system. You can also try pumping the head contents into the holding tank with the pumpout cap removed. If you aren’t met with resistance, that means the pumpout line is acting as the vent.

[tomo123]

Thanks for all the replies everyone. Not sure how long this has been happening since I bought the boat a few months ago and I think it's always been like this.

It shouldn't be pumping out to the ocean when I open the valve since there's a seacock that's closed which would prevent it from going out. The macerator is able to drain the tank which would probably mean it's venting somewhere.

I think the next thing I will try is make sure I have the valve in the correct position.
After watching that video I think I may have misunderstood the direction arrows and might be trying to pump it through the closed seacock when I think I have it pointed to the tank. If that isn't the issue then I'll open the inspection port, place the Y valve in the correct position and see if it works. That should confirm if it's a venting issue.

Probably won't be able to try this until the weekend but I'll report back what I find. Thanks for all the information

[Kelkara]

Originally Posted by tomo123

I think the next thing I will try is make sure I have the valve in the correct position.
After watching that video I think I may have misunderstood the direction arrows and might be trying to pump it through the closed seacock when I think I have it pointed to the tank. If that isn't the issue then I'll open the inspection port, place the Y valve in the correct position and see if it works.

In your photo, you can see the little grey arrows on the valve indicating the open flow path, the handle covers the arrow on the blocked path ... in the photo it is set to pump into the top right hose.

[tomo123]

After watching the previous video and some others I realized the arrows are where the flow goes and not where the handle is. This means I've had the handle in the wrong spot when trying to go to the tank. In my main picture the flow is going out the boat to the closed seacock and I thought it was going to the tank. This explains why it's impossible to pump until I crack the valve a little and it then rushes to the tank.

Really appreciate everyone's responses! Thanks!

[sinnerman]

My two cents:

If you are absolutely sure the vent is OK, not clogged:

- The line from the Y-Valve to the holding tank is clogged

- The Y-valve internally is clogged on the port going to the holding tank.

- The valve is not indexing correctly. You think it is set to the holding tank but it is not (internally) in the correct position.

The "vacuum releasing sound" is the pressure which built up in the line between the toilet pump and Y-valve (from the toilet pump) being released.

[OS2Dude]

Just to cover all the bases, are you POSITIVE that the Y Valve is plumbed correctly?

[sinnerman]

Closing comment (from me):
If you are pumping the toilet directly overboard, and the toilet is below the water line (including when boat is heeled over), you are supposed to have an anti-siphon loop in the discharge line.

This will prevent the possibility of the boat flooding by water flowing backwards through the toilet.

If possible, the vent on top of the anti-siphon loop should be vented overboard, to prevent the smell of "odorous excrement" entering the cabin.

Cheers