22mm Condensate Pipe Elbows Failing

[techweb]

Our boiler is in the loft and I encountered a leak in a roof above our side extension store room which has transpired to be from the boiler condensate pipe. It was cracked at an elbow so the plumber we use has replaced this and hopefully all will be well with that joint.

This later prompted me to look at others that I can see. One in the loft had also cracked badly so I asked him to change this. I also found one just prior to where it goes into the waste downstairs which was hairline and I smeared some silicone over for now.

Bottom line is it's likely the whole run has to be replaced as I can't have confidence in the elbows I can't see (particularly one that must be behind a stud wall) in one of the bedrooms.

I hope to get somebody with an endoscope to look down the void to see what the state of the elbow is and whether they used a compression fitting instead of a standard solvent weld elbow.

 

[gmartine]

If you don't trust the unseen pipework and joints and want to replace you could use some flexi condensate pipe instead and probably pull it through.

 

[techweb]

That's a good idea!

The only challenge might be fishing for it and getting it through a hole the other side of the cavity wall where the current solid pipe does. Or do you mean thread it through the existing plastic pipework to use as a guide?

 

[ShaunCorbs]

Seeing this more and more with overflow pipe if it’s not splitting it’s eating the glue etc

 

[gmartine]

That's a good idea!

The only challenge might be fishing for it and getting it through a hole the other side of the cavity wall where the current solid pipe does. Or do you mean thread it through the existing plastic pipework to use as a guide?

No, can't do that as it's about the same size. Difficult to say for certain without seeing it but I'd just remove the existing condensate pipe and use a cable threading kit to pull the flexi pipe through. They can be had for about a tenner if you're going to try it yourself but most tradesman should carry them.

 

[techweb]

No, can't do that as it's about the same size. Difficult to say for certain without seeing it but I'd just remove the existing condensate pipe and use a cable threading kit to pull the flexi pipe through. They can be had for about a tenner if you're going to try it yourself but most tradesman should carry them.

It could well be possible how you describe...

I saw that you can get 6mm condensate hoses but I think these are typically used with siphon pumps.

Challenge will be getting the old pipe out in the void. Once the end is cut off from the loft above the lean to extension, it would then be a case of trying to maneuver the pipe several feet up from the main loft, with the length of pipe still in the brick cavity. I guess it could be drilled out and disintegrated from the other side.

I'm no plumber so will be getting a plumber to do it.

 

[snowhead]

Is there another completely different route a new pipe could be run, maybe to a different drain?

 

[gmartine]

...yeah, or leave most of existing condensate pipe in situ and use another route to the same termination point. Might not be as tidy but you won't see it.

 

[techweb]

...yeah, or leave most of existing condensate pipe in situ and use another route to the same termination point. Might not be as tidy but you won't see it.

Other routes are possible I guess, even further along the stud wall but will still require fishing for the pipe and bringing it into the loft.

Worst case a hole will have to be cut in it but it's a shame as it has a mural / feature paper on the wall. Not catastrophic but if it can avoided then it would be better. Bottom line is, once done, I want to this once and it last 20+ years. This system is 13 years old and was installed by previous occupants as part of a renovation. I noticed that one elbow in loft was replaced in an exposed location prior to us moving in 4 years ago. It seems this 22mm overflow pipe and fixings are not great and / or the installation was questionable.

 

[gmartine]

Seems to be a long term material compatibility issue between adhesive & condensate. Nobody's fault just unfortunate, well perhaps the adhesive manufacturer. See what your plumber has to say, he may be able to suggest an alternative route.

 

[techweb]

Seems to be a long term material compatibility issue between adhesive & condensate. Nobody's fault just unfortunate, well perhaps the adhesive manufacturer. See what your plumber has to say, he may be able to suggest an alternative route.

In my case, it seems failure of the elbows is the issue, as in they have cracked over time. My plumber suggested replacing the entire run and cutting into the stud wall to effect the replacement. Of course this is an easier thing to do rather than trying to fish for flexible cable etc but I will put this to him as an alternative.

 

[Ben-gee]

Can you attach a thin tough rope/string ( I use 4mm polypropylene line) to the existing pipe and then pull the pipe out from the other end - so you end up with the string along the route you want.
Then attach the new flexi pipe to the line and pull it through.

 

[techweb]

Can you attach a thin tough rope/string ( I use 4mm polypropylene line) to the existing pipe and then pull the pipe out from the other end - so you end up with the string along the route you want.
Then attach the new flexi pipe to the line and pull it through.

If the existing pipe was flexible, this would be an option. However, as the existing pipe is 22mm overflow pipe and it goes through a cavity, to pull it out between the wall and stud wall with limited access in the loft would be I suspect impossible.

I think fishing for a new flexible hose would be an option though...

What hose options exist? I would need a ~15m run.

 

[Ben-gee]

I think I’d be looking for a new route for the pipework in that case.

 

[techweb]

I think I’d be looking for a new route for the pipework in that case.

Any ideas on a flexible hose to use for this?

 

[gmartine]

The elbows are failing because the condensate (acidic) seems to be eventually reacting with the adhesive, there can't be any other reason for for elbows spliting and failing like that.
Given the length of run it might just be easier to install a condensate pump (if necesssary) and run it to a rainwater downpipe else where outside the building?

 

[techweb]

The elbows are failing because the condensate (acidic) seems to be eventually reacting with the adhesive, there can't be any other reason for for elbows spliting and failing like that.
Given the length of run it might just be easier to install a condensate pump (if necesssary) and run it to a rainwater downpipe else where outside the building?

I'd prefer to keep the run internal and use a flexible hose. The question is however which hose would be suitable for this application? It seems most are either 22 or 32 mm solid pipes.

I'll call a plumbers merchants to see what options they have and then discuss with my plumber.

 

[gmartine]

Not sure you can officially find flexi condensate pipe in much longer than 3m tbf.

It might require a little creative thinking and find say conduit that can be bought in much longer lengths, due diligence required as to the materials properties and resistance to condensate.