Alpha CD50 leak

[ChrisJB]

I have an Alpha CD50 boiler which is 4.5 years old. It is leaking water from the top of the manifold for the primary pressure switch and the heating pressure relief valve. The leak is quite slow at present, maybe 1 millilitre per hour. The leak is where the pipe is fixed to the manifold.

The qualified installer who fitted it says this joint is sealed with an O ring in the annulus between the pipe and the manifold bore. There's no way the manifold can be moved so to replace the O ring the pipe must be lifted upward - the pipe forks so there are two other joints which need to be released. There are no instructions in the user manual (the 40 page one) for this task. The pipe disappears behind the heating pressure vessel which I assume will have to come out, not sure whether there's anything else to be removed.

Can anyone advise me on what might have to be done and whether this is something I can DiY? I have some plumbing experience and DiY most things.

Thanks

 

[colinwel]

hi there , i have exactly the same problem now. did you solve yours and if so - how? cheers colin

 

[ChrisJB]

Hi Colin,

After discussion with my installer, we thought it possible to remove the pressure vessel and a few other bits, and probably get to the pipe and undo the branch to the combustion chamber and the top connection, remove the pipe, replace the O ring. But he didn't want to do it, and I wasn't going to attempt it when the temperature outside was -5ºC and I needed the boiler in working order.

So I went to B&Q and bought some O rings and a tube of an epoxy compound called Plumbers Mait (spelt like that) designed for sealing copper pipe leaks. I cut an O ring and took a piece out so that it was exactly the right diameter to fit round the pipe, then using various tools pushed it into the annulus where the leak was, until it sat on the securing pin. Then I mixed some of the epoxy and pushed it in on top of the O ring, and made a 45º fillet round the top.

I had expected I would have to drain the circuit and use compressed air to dry the annulus, but because it was so cold outside the heating was running almost continuously, and there was enough waste heat to dry the leak. As the water evaporated it left a thick goo (I assume it was from the Sentinel additive) which help seal it while the epoxy set.

It's been fine since - when we get to June I'll decide whether to leave it or strip the boiler down and fix it properly. The purpose of the split O ring I pushed in was to help seal but also to stop the epoxy getting onto the securing pin and deep into the fitting - so I should be able to clean it up if I decide to go that way.

Chris

 

[Agile]

I cannot disagree that this has solved the leak for the moment.

However, I would hope that no professional boiler engineer would ever attempt a bodge like that.

Many of those boilers had a five year warrantee. Was that aspect checked?

Tony

 

[colinwel]

thanks for that but mines leaking through the securing pin so it looks like a strip down is the only solution .awkward job just for an o ring! thanks colin

 

[ChrisJB]

Thanks Tony - 3 year warranty only, unfortunately.

I can quite understand why nobody would do that type of fix professionally but in that situation it was the right fix so I had to do it myself. It just was not worth the risk of swapping a minor nuisance leak for a potentially shut down system. If, for example, a part was unexpectedly damaged during strip down and wasn't available, or the system didn't re-commission properly after draining (both of which have happened to me in the past) having somebody to blame wouldn't be any consolation for a frozen family. Come summer, my intention is that it will be stripped down and have a new O ring.

Colin - I did have a very minor weep from the pin but it sealed itself with the goo I mentioned. Good luck with the job, I'd be interested to know how it went.

Chris

 

[mazdadriver1]

Hello, I have a 4 yr old Alpha CD50 which was "leaking" too. My installer fitter a new sealing washer as mentioned in other posts on here. This in itself isn't a too big of a job really, it took him longer to remove the front and side panels, then to gain further access the inner panel had to be removed. However, within 24 hrs, my boiler was leaking again. The problem in my case was water collecting in the outer flue pipe (possibly rainwater) and flowing down the pipe at the flue sample point, at the top of the boiler (see installation guide). The other end of this clear semi rubber pipe was laying loose on the horizontal bulkhead. It appears that the collection of water in the outer flue pipe was travelling back into the boiler and simply spilling inside the boiler making it look like the boiler itself was leaking. With the weight of water in the outer flue pipe it had pulled the flue down, therefore more water was allowed to be trapped. The flue pipe has now been emptied and a support is to be fitted. Also, I have extended the sample pipe to run out through the condensate outlet. Hopefully I shouldn't have any more problems. I hope my experience can help someone out there.