Plumbing under sink

[SusanDuke]

Having problems with water coming up the pipe where the condensing boiler pipe goes into, I’ve cleared all bits of crap that was in all the pipes from the sink right out to drain outside, when I run the tap water is going out to the drain outside at usual rate but it’s going up and out of pipe, the boiler pipe has been there for over 8 yrs and never had water come out of it, can anyone help

 

[Ivor Windybottom]

That pipe should not just be placed in . it needs a proper fitting put on it and sealed

That's the answer. You need a proper joint there, not just a small pipe popped into a bigger one. It's a botch job.

For whatever reason the waste is flowing slightly slower than it was in the past - possibly a partial blockage that may be just temporary, or perhaps some other minor factor. But that's almost irrelevant, either it just about worked OK in the past or occasionally leaked and you didn't notice. But this definitely needs to be sealed, as it stands the sink is able to empty into the cupboard.

It looks like standard toilet overflow pipe, going into 1-1/4" pipe. But I'm not a plumber, if someone knows better please correct me. There will hopefully be a compression fitting available for exactly this job, which presumably your boiler fitter didn't have in the saddlebag of his horse.

You should be able to find a fitting from B&Q, Screwfix, Toolstation etc. Sometimes it may be a rubber plug that pushes into the socket of the bigger size, e.g. you fit a standard 1-1/4" waste pipe coupler with a rubber bung in one end that has a hole the right size for the other pipe. It all gets squeezed sealed when you tighten the coupler.