Fixing crack in metal

[emailrob]

I have a crack of about 4 inches in the small red tank at the back of my combi boiler. This has resulted in dripping water.

The plumber (somewhat unsurprisingly) said the whole thing needs replacing.

Is it possible to repair the crack, at least to stop it dripping for a few months? The house is for sale so I don't really want to fork out £800 for a new one unless absolutely necessary.

I have some epoxy resin which I have tried to repair but not sure how well this bonds to the crack.

Any advice on what to use / whether epoxy will work at all.
The red tank is really hard to get to, so I have to partly do it blindly.

thanks in advance

Robert

 

[Ant]

The red tank on my combi is actually a pressure vessel (it is round and about 15 inches across by 4 inches thick approx) it has one feed in and a schraeder type valve at the top. Does this sound similar? This actually is pressurised so I think trying to seal it up may be difficult as it may crack again. I had to replace mine as the "balloon" inside it was leaking - it cost around £100. The figure you quoted seems a hell of a lot! - What kind of boiler is it and how much is a new one? It may be worth trying to fix at that kind of a price but try phoning around suppliers as if you can DIY you could maybe save a lot. I got mine from a company called HRPC (Heating Components and Replacement Parts) I will dig out their number if you want it.

 

[emailrob]

Yeah, I think it is a pressure valve, sounds familiar.
I just wondered whether sealing it up would work, I would rather have a go with a £5 sealant first, then if it still does not work get the part replaced.

Not had any experience with epoxy and sealants for these purposes, so wondered whether they were any good. I know you can get stuff that seals copper pipes...?

 

[breezer]

I am not a plumber or heating engineer but the pressure in your expansion vessel will probably cause it to either get worse or "blow off" hat ever you put on it to seal it.

get a 2nd opinion as to fitting either a replacement or an additional one and removing the old one

 

[ogoshi]

The most sensible thing to do would be to have the expansoin vessel changed.If you have a good look you will see that it will be quiet straight forward to remove,perhaps by removing a side panel of the boiler,usually its pretty straight forward.If you try to seal it and it leaks again it might damage other components,circuit board etc,which will cost more.Best to cut your losses and do it properly.
Also you mentioned £800.If that is for replacing the expansion vessel then that is way over priced.If its for a replacement combi then you should get a couple more quotes as thats quite excessive.

 

[emailrob]

OK Cheers guys, I guess I need to replace the vessel or the whole thing

;-(

thanks for all the help

 

[Ant]

As ogoshi says, it is usually fairly easy to replace yourself. On my boiler I think there was only one connection to get to and after removing the side panel to allow the vessel to be taken out it was a simple bolt up job to put in the new one. Unless the boiler is really old or knackered I would have a look at a replacement. What boiler is it by the way?

 

[emailrob]

It's a glowworm something or other, cannot remember the model. It's about 10 years old.

I will try and source the part. I'm concerned that if I take it out water will come out everywhere!!! are there precautions I need to take here?

 

[Ant]

You will have to drain down the boiler, not a major job, and refill/bleed afterwards. Check the manual or contact manufacturer technical dept for exact method.

 

[emailrob]

thanks peeps, good advice as always.