Combi boiler condensate pipe leaking / overflowing

[joropug]

I've noticed our boiler (Vaillant combi) was leaking water below it inside the house. A bit of detective work found its the condensate pipe.

However, it seems to be overflowing. By that I mean the condensate pipe fits OVER the outlet and water is coming up in drips and the running down the exterior of the pipe.

The pipe ends up at the kitchen sink internally.

The only thing I can think of is that the pipe is somehow blocked but I don't know...is that a thing ?

Any help greatly appreciated.

(It's the white plastic pipe)

[Lincsls1]

Be as sure as you can that there isn't an issue with the pipe at the boiler end, as in it has dropped a fraction or there is a tiny crack.
Assuming all is well, yes it is perfectly possible for the water to be backing up if the connection at the sink drain is part blocked.
I have seen it many times and it is typically fat/gunk deposits from the other sources that meet at the junction and your 22mm end is easily blocked.

[joropug]

Thanks. I'm going to turn it off and remove the white pipe tonight and trace it to the sink, try and find a blockage which I assume will be at one end or the other, unless the pipe isn't flat and it's collecting somewhere.

It's been alright for 6 years so I am hoping it is just a build up/block

[Lincsls1]

Like I said, its more likely to be a build up of 'gunk' at the sink end rather than the boiler connection.
Good luck!

[joropug]

Thanks for the help , learned a lot never even looked at this stuff before.

Removed the pipe with my Dad, it was pretty clear. We disconnected it at the sink end , poured water in and it came out of the sink end = no blockage.



After turning it on with he pipe removed we confirmed the water was coming from inside the pipe so hadn't broken off on the boiler side fortunately.

Decided the pipe was perhaps not quite long enough. Nipped to b&q, bought a new push fit connector and pipe.

Had a massive disappointment after cutting it to realise it has another layer inside the new pipe which meant it didn't fit....but had a stroke of genius. Got a heat gun on it, warmed it right up and it fit on nicely. Hopefully as it cools it'll contract nice and tight too. After testing it seems to have fixed the problem, combo of a tighter fit and slightly taller pipe.

[Lincsls1]

Nice work there chap. Hope that's the end of your problem.
Did you confirm that the actual sink waste part was all clear too by poking around inside the connection?

[joropug]

Yeah all good wiggled a wire up there good flow through the pipe.

It's held up fine so resolved !

[Sheepshanks]

Hard to tell from the pictures, but the original tube looked like it was reasonably pushed onto the stub from the boiler, so I must admit I was sure it must be blocked. Was it only just hanging on by whisker?

[joropug]

Well the original pipe was cut slightly wonky, turning on the boiler without a pipe you can see the water runs down the left hand side as you're looking at it.

What the water seemed to do was then flick left from the surface tension and somehow defy gravity.

Kinda like when you pour water out of a glass, goes everywhere but where you want it.

The water level in the downward pipe matched the height of where it connects to the sink too