Plumbing mystery going on 2 years :(

[sophroll]

hello all!

desperately looking for some help from experienced plumbers. not sure how much to include so i will just put it all out there.

- moved in to home 2 years ago

- home has 2 bathrooms upstairs and the toilets are back to back; both toilets were new purchased by us and installed when we moved in

- after using both toilets for about a month, they started acting weird; when flushed, a toilet will bubble up from the center of the bowl (big bubbles like you see when you use a water cooler). the toilet then fills very full and then drains very slowly, but all the waste doesn't go down. after draining there is only an inch or so left in the bowl altogether.

- mystery part is that both toilets will do this, but they take turns. as in one will do it for a while and then one day it will switch over and the other one will do it. although it does seem to be one more than the other mostly.

- unrelated to the problem but still useful info, about a year after moving in, we had a leak in the ceiling from a baseboard nail going through a pipe so we had to open up the ceiling and you can see all of the plumbing to the upstairs bathrooms. because of this issue the toilet was removed to repair the pipe behind it for the leak. while this toilet was removed and therefore no toilet was being used, the other toilet NEVER had any problems.

- we've had about six plumbers come look, and because the ceiling is open where all the upstairs plumbing is, they can see how our pipes look and all say pipes and config of pipes look fine

- one plumber said, "it's because you have two low flow toilets back to back" so we replaced one of the toilets (the one that acted up more, in the master) and it didn't fix anything

- one said it was the venting. we have 2 vents for a total of two toilets, 2 sinks and a shower and bathtub. they said we needed more vents and the job was quoted at $3500. happy to do this really if it will fix problem, but we live in townhomes and literally everyone else has this config in their units (you can see all the vents on the roofs of other units and they all have 2 like us). scared to spend $3500 is it's not the issue

- HELP! if you have any insight we are all ears.

thank you!

 

[Plumber69]

When one of your toilets was removed it acted as a vent for the other. You clearly need a vent

 

[Sponsor]

 

[Plumber69]

Take a pic

 

[sophroll]

Here are some pics and some diagrams... when I looked I actually don’t see the double wye fitting mentioned in the first reply. Hopefully my kid drawings are helpful but who knows! Drawing with blue is as if you’re laying on floor and looking up

 

[sophroll]

Sorry the double wye was not referenced here as I noted in that reply... but someone else said I should have a double wye 45 degree fitting. I don’t see it but don’t know enough to know if I would?

 

[Terry]

The double wye fitting is normally installed on the vertical. You have your lines on the horizontal with wye fittings. That part should be good. Assuming the lav is wet venting things. It's still a bit of a guess without seeing the venting. It's not obviously bad though.

 

[sophroll]

The double wye fitting is normally installed on the vertical. You have your lines on the horizontal with wye fittings. That part should be good. Assuming the lav is wet venting things. It's still a bit of a guess without seeing the venting. It's not obviously bad though.

Would you recommend opening the wall behind one toilet to see what the wye fitting looks like? We have to have sheetrockers patch it up anyway bc of the leak so what’s a few more feet of damage...

 

[Plumber69]

If your lavs don't have vents it could be the issue. Easy way to tell is to drain all the water from the ptraps.... or take ptraps off the sinks. Then try flushing.