Under sink plumbing

[NickB_99]

Hi,

Hoping for some advice on the setup of the waste under the sink.

Untitled

• NickB_99
• 9 Feb 2014
• 1

When the washer feeds in as it's draining, it's temporarily backing up into main and half bowl sinks above.

I've had it apart where I can get to (all the white pipework and the black push fit to where it goes to the cupboard back). There is no obvious blockage through to here.
The horizontal run of black pipe seems to go straight through to outside to a 90 deg elbow and then straight down to drain.
When it's light I can have a go from the other end.

My question is about the section post-Ubend - is this section that bends back up potentially causing resistance to the flow?

The installation has been in a few years, and it's not been a problem before. Just wondering if it is a poor design not helping.

Thanks.

 

[Whitespirit66]

If it was OK before, the design was OK. There is a partial blockage in the pipes between the u bend and drain. Or, the drain's gully outside maybe blocked with fat, etc. Does the water level rise up to the grate outside.

If it's a hidden block in the plastc waste, a flexible metal drain unblocking tool from somewhere like Toolstation will shift it.

http://www.toolstation.com/shop/Hand Tools/Plumbers Tools/Waste Pipe Cleaner/d10/sd210/p80592

 

[NickB_99]

If it was OK before, the design was OK. There is a partial blockage in the pipes between the u bend and drain. Or, the drain's gully outside maybe blocked with fat, etc. Does the water level rise up to the grate outside.

If it's a hidden block in the plastc waste, a flexible metal drain unblocking tool from somewhere like Toolstation will shift it.

http://www.toolstation.com/shop/Han...s/Waste Pipe Cleaner/d10/sd210/p80592[/QUOTE]

Thanks for the prompt feedback.
I'll leave the design as it is.
I think you are right with the partial blockage - I'll look up a tool as you suggest. The pipe outside has a gap before it drops into the drain, so if blocked in there, I'd expect would have overflowed the drain and gone elsewhere.