Air lock

[Madrab]

As suggested a snake could have cut through a blockage or moved some of a restriction but it may not have cleared it all and therefore there could still be a restriction causing back pressure, creating enough pressure to slow or stop the flow until the airlock is broken.

Won't really know until you work your way back from the shower if it won't clear any other way. I presume the trap and linear waste etc is squeaky clean?

 

[dilalio]

You are right, it can’t starts air locking if it worked before. But how would you explain it, no obstruction as I borrowed a k45 machine and put the snake through until it appeared in the stack so the pipe is 100% clear. I think it could be the one shot I put and it damaged the pipe or it caused it to dip somehow so when air is introduced by the pump action, it flows freely. I am thinking of taking the floor up and replace the drain pipe

Have you removed the AAV?

 

[Matti]

Yes I have and same results