I am an apartment manager of a 17 unit building. Currrently one of my tenants has been having trouble with her toilet not flushing. This is what we have done so far.

It was snaked out by 2 plumbers going down they said 3 feet. - didn't work.

Came back again, took the toilet off and snaked down 8 feet, also used the camera and found nothing so he said it probably was a bad toilet so we replaced the whole toilet, tank and everything. Still not working.

The problem is when she flushes, sometime it doesn't swirl and sometime it swirls but seems like there is no pressure for the waste to go down. She has changed the toilet paper she used now uses single ply paper.

Right now she is adding water to the toilet to make everything go down,

Can you help with what else could be wrong. Our owner said without any other tenants having trouble it couldn't be the venting.

Thank you!!

Maybe its not the plumbing, it's the tenant. I have run across many situations where the toilet just gets overloaded by whatever. Is this a couple with kids? How long have they been there and how long has this problem existed?