Rear Exit toilet not fully flushing, SHORT run to vent stack.

[Gilligan8]

So, I have a new to me home that the master bath had a rear exit toilet that flushed "ok". I assumed it didn't pull on the vacuum of the P-Trap due to the short run to the vent stack.
But now it seems to not be even getting close to pulling all the way down.
I'm posting a video (link) and a picture of the outside. The wall is like 10" thick, so keep that in mind with the picture you see and I'm aware that I need to protect the PEX from the elements... again, just moved in a few weeks ago and it's on the list of things to do (will likely replace them since I don't know how long they have been exposed to UV).

 

[John Gayewski]

Can you adjust the water level in the tank to go higher? If so try that.

It looks to me like there's no siphon jet at the bottom of the bowl on this toilet. This means all of the water needed to form a siphon needs to rush down from above and into the bowl through the rim jets. These tiny holes can become fully or partiality blocked over time. Try cleaning the holes with a tool and some vinegar also dumping some vinegar in the tank and cycling it a few times after you clean it.

 

[Sponsor]

 

[Gilligan8]

Can you adjust the water level in the tank to go higher? If so try that.

It looks to me like there's no siphon jet at the bottom of the bowl on this toilet. This means all of the water needed to form a siphon needs to rush down from above and into the bowl through the rim jets. These tiny holes can become fully or partiality blocked over time. Try cleaning the holes with a tool and some vinegar also dumping some vinegar in the tank and cycling it a few times after you clean it.

Ok, so I have a Briggs Vacuity system.

That is why there is no siphon jet in the bowl, it happens from the tank.

How the Briggs Vacuity works

Now there is a special way to plunge this, and I have done that and I am still having the same issue.

It swirls pretty strongly but never really empties very strongly.

Any other ideas?

 

[John Gayewski]

Ok, so I have a Briggs Vacuity system.

That is why there is no siphon jet in the bowl, it happens from the tank.

How the Briggs Vacuity works

Now there is a special way to plunge this, and I have done that and I am still having the same issue.

It swirls pretty strongly but never really empties very strongly.

Any other ideas?

Clean the holes, cool the tank completely, like I said.

 

[Gilligan8]

Ok... back.

Have not to clean it out but I did the next best thing.

I flushed it and poured over 4 gallons of water into the bowl at the same time, bringing the water level right up to the bottom of the rim.

Still just drained the water out and didn't draw down like a normal toilet would flush. I was able to pour it in pretty quickly so it's also not a clog, just no vacuum draw down. I do hear the air moving in the vacuum stand pipe thing so that isn't clogged either.

So it's not related to the volume of water being put in via the tank nor the ability to put water in fast enough via the holes under the rim.

I also added a cleanout right above that Y and before I put it I had the wife flush while I stood and watched. Water flowed very freely (and cleanly) we had a bit of toilet tissue in there and it just slowly spun and slinked it's way down like it always does.

Any other ideas?

 

[John Gayewski]

Is the toilet taking all of the waste with it? Or is there waste being left behind?

 

[Gilligan8]

In case anyone finds this and is having the same problem, it was the gasket from the vacuity tube that wasn't sealing well.

Found a new one and replaced both gaskets between the tank and the bowel and it works now.

 

[John Gayewski]

In case anyone finds this and is having the same problem, it was the gasket from the vacuity tube that wasn't sealing well.

Found a new one and replaced both gaskets between the tank and the bowel and it works now.

These toilets aren't legal under the upc and I would guess because of that they are rare.