Plumbing basics

[vivienz]

I noticed a leak from our washing machine waste pipe, on the upper entry side to the u-bend. It's been leaking for a while, as you can see from the effect on the plasterboard.

 

What's the best way to seal this?

 

I should add that I can't loosen the joint.

 

[ProDave]

That should be a compression joint with a (usually tapered) rubber sealing ring, and it should only be hand tight.  The fact you can't undo it, suggests the proper sealing ring is missing or damaged and it has been bodged.

 

A replacement is not expensive https://www.ebay.co.uk/itm/WASHING-MACHINE-DISHWASHER-STAND-PIPE-TRAP-40mm-WITH-CLIPS-brand-new/273825602547?hash=item3fc1471bf3:g:RQcAAOSwKOZb-xGu

[joe90]

Or even cheaper in Screwfix and cheaper again in toolstation.

[Tennentslager]

I’d open it up and have a look for a twisted or missing seal, should have a black rubber one and a red washer. The rubber one is tapered and the red one more rigid and helps push the rubber into the right place as you tighten the compression nut.

if you un-tighten everything a couple of twists it should give wriggle room to disassemble it 

[joe90]

24 minutes ago, Tennentslager said:

I’d open it up and have a look for a twisted or missing seal, should have a black rubber one and a red washer. The rubber one is tapered and the red one more rigid and helps push the rubber into the right place as you tighten the compression nut.

if you un-tighten everything a couple of twists it should give wriggle room to disassemble it 

 

On some of these there is only a clear tapered seal at that joint and no red washer, rather flimsy and easy to get wrong (ask me how I know?).if it’s that tight someone has used a wrench to try to stop the leak.

Edited October 19, 2019 by joe90

[vivienz]

Ah, thanks chaps. OH has managed to get it undone and there is no washer. Looks like a trip to Screwfix.

[Onoff]

Random pic off the web. Note how the black, tapered washer fits. The red fibre washer compresses the black one without turning it. Hand tight only as above: