Sink overflow with washing machine/horizontal run/AAV

[Hobsy85]

My sink is draining slowly.


My washing machine is pumping water up into the sink and overflowing it.


I believe this is caused by drain blockage. I'm pretty sure this is caused by drain blockage. The waste pipe comes down from the sink, through a t-piece between the sink and trap (where the washing machine joins) then after a .4m drop, along a 10m long near horizontal stretch before it leaves the building through the bathroom wall and joins the soil stack.


I called a guy in from DynoRod to jet the pipe out. He removed the AAV, and noticed that the sink was now draining properly. That lead him to suggest that my problem was with the AAV, not blocked drains. He didn't charge anything. That was good.


I took the AAV apart. It was wet, so the valve was sticking. So I bought a new one, fitted it. It's not solved the problem.


So is the problem with the placement of the AAV (should they be getting wet on the inside?) or with drain blockage (seems likely, given the 10m horizontal section) or both? Can a drain like this be jetted?

Any advice or suggestions would be very much appreciated.

 

[Simon F]

welcome to the forum Hobsy85.
10m pipe, near horizontal! what size is it??
I would be looking at the pipe

 

[Hobsy85]

welcome to the forum Hobsy85.
10m pipe, near horizontal! what size is it??
I would be looking at the pipe

It's 40mm.

Yeah, brilliant, right? I don't know who's smart idea that was.

 

[PlumbBobBob]

can you get to the pipe along it's entire length? maybe think about increasing it to 50mm.

 

[Hobsy85]

can you get to the pipe along it's entire length? maybe think about increasing it to 50mm.

Unfortunately not. It's all boxed in. And seeing as it's rented property, I don't want to go ripping it apart.

I've used some more caustic soda and run a load of hot water through and now I'm able to use the washing machine without it backing up into the sink. So it was definitely a blockage in the pipe and not a problem with the AAV. I guess I'll just keep an eye on it for now, and when it gets bad again I'll call someone in again to jet it (and explain to them that the problem is a blockage and not a faulty AAV).

 

[PlumbBobBob]

that's good then. maybe keep some in the cupboard for next time, or do a regular application every couple of months to keep the flow clear.

 

[Phil]

Ah .....the old gunked up ten mile run of horizontal 40mm we meet again my old freind. Sounds like a job for my wet vac for starters but be prepared for untold stench.

 

[PlumbBobBob]

Ah .....the old gunked up ten mile run of horizontal 40mm we meet again my old freind. Sounds like a job for my wet vac for starters but be prepared for untold stench.

nothing quite like drains stench

 

[Howsie]

I'd be having a word with the landlord. This is his problem(and cost) to resolve.

 

[Ermintrude]

nothing quite like drains stench

Urinals with that lovely yellow pipe lining. Makes your eyes water.

 

[PlumbBobBob]

Urinals with that lovely yellow pipe lining. Makes your eyes water.

i've not had the pleasure or should that be displeasure

 

[Ermintrude]

U haven't lived.

Lift bog out put in area by sink while ur fanning about in stall with panels to get into work and some drunk emo takes a leak in it.