Ways to clear the condensate pipe

[Jilly]

Our fairly new Worcester Boch LPG boiler started making boiling sounds. Its under guarantee so the repair chap has just been and diagnosed a blocked condensate pipe, which I need to get cleared and replaced.

 

It runs behind the cupboards and fits into the sink waste with quite a few bends so maybe this is  the cause.

 

I've been trying to send lots of hot water and bicarbonate of soda (I'll go and get some caustic soda), but it doesn't seem to be doing the trick (and I suppose could be pushing more gunk back up as I can't blow it (boiler man told me not to so I don't invalidate the warranty). ?

 

Any other suggestions please folks?

 

[Jilly]

[Nickfromwales]

Undo the white nut, below the solvent weld elbow. Have an old towel stuffed in there to catch any water trapped in the pipe. The nut should be a little over hand tight, so you should be able to remove this with relative ease.

 

Get a pipe cleaner or similar and then insert it down and around the elbow fitting ( white bit connected to the black pipe ) as I know British Gas for one fit a stupid and unnecessary ( plus problematic  ) non-return valve at these junctions. You should feel an 'obstruction' in the elbow, and if so you will need to get the non return guts removed and then just re-fit the nut and pipe back on. That will be the end of the problem I think.

 

I've been out and removed loads of these tbh with identical symptoms. BG even install these outdoors, uninsulated, and as they harbour a little residual water at the lowest part of the pipe, they then instantly freeze!! 

[Nickfromwales]

The best option is to cut into the black pipe and fit a solvent T with a reducer to 21.5mm ( condensate pipe ) glued into it. Those retro-fit connectors are shite tbh. This would be fit and forget then. 30 min job at most. Can't you get the boiler installer / plumber back to do this?

[Jilly]

Ok I’ll try that thank you! 

[Nickfromwales]

Just cover that power point properly first.  

[Mr Punter]

I had a similar issue and connected a hose to the pipe inside the boiler and ran it through.  Go steady at first, then increase the flow.

[Jilly]

Yay, I’ve done it! Thank you! Yep, with  lots of towels and circuit off. There wasn’t a lot of gunk really, so I could do that again, but I’ll be more careful with cleaning the drain and maybe it’ll be less likely to recur. 
The WB repair man blew down the pipe but wouldn’t show me how. I had a look after he’d gone and noticed he left the rubber pipe off the condensate bottle thingy. 

The boiler installer was the non LPG chap who caused a bit of worry at the beginning, so I’m not sure about him 😔

[Nickfromwales]

36 minutes ago, Jilly said:

Yay, I’ve done it! Thank you! Yep, with  lots of towels and circuit off. There wasn’t a lot of gunk really, so I could do that again, but I’ll be more careful with cleaning the drain and maybe it’ll be less likely to recur. 
The WB repair man blew down the pipe but wouldn’t show me how. I had a look after he’d gone and noticed he left the rubber pipe off the condensate bottle thingy. 

The boiler installer was the non LPG chap who caused a bit of worry at the beginning, so I’m not sure about him 😔

Happy days!   Problem solved, and cost-effective to boot lol.

Where was the gunk? In the connector or pipe? Is it a kitchen sink waste pipe? If so, it is likely that it is food debris that is pushing back into the small condensate connector each time you swill the sink. I would get the connector changed out as I say above. Should be a lifetime of zero issues then.

 

[Jilly]

The gunk I cleared was in the part near the main sink drain (eek I didn't actually check back up the condensate pipe and it pointed down and nothing came out...)

 

If we used something that was glued in there would be no way to clean it out if it happened again, or have I missed something?

 

[Nickfromwales]

11 minutes ago, Jilly said:

The gunk I cleared was in the part near the main sink drain (eek I didn't actually check back up the condensate pipe and it pointed down and nothing came out...)

 

If we used something that was glued in there would be no way to clean it out if it happened again, or have I missed something?

 

There is nothing that will come out of the boiler that will block this pipe. The "gunk" is coming from the water / food debris etc from the sink, and it is that which is causing the issue. It is a rather shitty place to T the condensate pipe in tbh. Also, the type of connector used  ( LINK ) means typically the installer will make a smaller hole than the bore of the condensate pipe so as to avoid an ill-fitting joint / seal via the rubber insert, so that is now a choke point too. 

Then add to that, that lazy bastard plumbers don't bother to ream out the inside of the freshly cut hole, in black pipe, to remove all the swarf from cutting into it, and there's all the things that come together to create your issue(s).

 

If you use solvent weld fittings, all at the full bore, reducing from the black pipe size ( assuming its an 1 1/2" waste pipe aka 40mm, then that goes into the dog-leg, still at 40mm, and then when elevated it converts to 21.5mm to take the condensate pipe directly inwards. So basically, you're re-doing the dog-leg, but in the larger pipe size, ergo the food waste cant block the small hole that the plumber drilled out.

[Jilly]

Ah ok, thank you!