Hairline crack in CH boiler

We have a very ancient gas boiler that is well past its sell by date and it has developed a small hairline crack on the outside of the cast heat exchanger that spurts a fine stream of water when the boiler is running.

The replacement of the boiler in the short term is not a budgeted option.

Question therefore is there an epoxy or similar that could effect a repair to get us through Christmas ?

Edited By Alan Wood 4 on 08/12/2020 19:57:29

Sorry to break it to you, but classed as ‘immediately dangerous’ in the trade. Any attempt at repair would be a bodge. My advice is don’t use it, sell a kidney or whatever it takes and get a new one.

If it was mine, I'd be very tempted to try one of the leak sealers first - not much lost if it doesn't work, although it does sound like your leak may be too big for it to have much hope.

Or there's always metal-stitching, but I guess you'd be fast approaching the cost of a new boiler with that.

In which case I'd recommend Intergas, can be set up as a pressurised or system boiler.

Rob

While I would agre that repair is not a good idea, it is possible if really desperate.

The info below is just an idea, you must make your own assesssment and choice. If you do this I accept NO RESPONSIBILITY for any damage or injury. IT IS AT YOUR RISK!

A capillary action sealant such as Loctite 290 could be used
https://www.henkel-adhesives.com/us/en/product/threadlockers/loctite_290.html
Note it says " The product can also fill porosities in welds, castings and powdered metal parts "
It is good to 150 deg C.
Applying it is another matter. You need to drain the system to below the crack and dry the crack completely. A hot air gun (paint stripper) is ideal for this. Then let it cool to about 30-40 deg C (just warm to touch) before appplying loctite. Wet the crack fully for several seconds but mop up any drips or runs. Leave for 5 mins, wipe off surface then leave as long as possible, ideally >3 hours before refilling system.
If the boiler leaks after this or starts to leak again stop using it as the crack may be growing.
In any case REPLaCE THE BOILER AS SOON AS POSSIBLE!

Flame suit on.

Robert G8RPI.

Edited By Robert Atkinson 2 on 08/12/2020 21:06:47

Don't even think about it.

Somehow, you need to find a 'used' direct replacement, usual source, plumbers, etc.

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What is the point of sensoring an O P when the rest still works????

This is obviously not a pressurised boiler so leak sealer may work, B&Q etc etc , works for holes in radiators.

It would appear from your post that this leak only ‘spurts’ while the boiler is operational. That likely means it is leaking more slowly when off/cold?

Heating may be enlarging the crack due to expansion stresses or the circulation pump is creating rather more pressure than just the static head. If the crack is elongating at each heat cycle the problem may escalate more quickly as time progresses.

The liklihood is that you will suffer a serious flood in the imminent future. Most systems are well protected from explosion but an old boiler may have an inoperative PRV and/or non-functional shut down in the case of over-heat. There may also be a risk with water around electrical parts.

The obvious routes are to change the heat exchanger or the complete installation.

If it is a short term problem with money, your bank will likely provide an overdraft facility which will only cost while overdrawn - not like a hire purchase contract (or loan sharks!).

Doing nothing is a risky choice. Trying to repair is likewise usually a futile exercise and might make things worse.

Total failure over the Christmas/New Year period might double or treble the labour costs involved.

My advice is to get it fixed pronto. Further, insurance companies don’t like claims where the failure is known to be imminent and still ignored - and have been known to decline cover in those situations.

As to boiler replacement you do not have to have a Combi if you don't want one

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As to boiler replacement you do not have to have a Combi if you don't want one

Dave is right on that one. No need to install a condensing boiler either.

I decided on a usual slightly lower efficiency balanced flue type when my previous boiler failed. That was about 15 years ago. I doubt a newfangled boiler would have made any savings in that period because the boiler does not get very much use - and any new fangled boiler would likely have needed changing again since then!

Edited By not done it yet on 09/12/2020 14:54:33

The non insurance employed members seem to know better.

Please don’t include me in that lot. I am for insurance, but I don't necessarily trust the insurance companies, particularly the cut-price ones. They try to reduce any claim by as much as they possibly can.

It also helps, if you quote me, to change the font or use inverted commas to show it is not part of your posting.

Recent changes to boiler regs

I decided on a usual slightly lower efficiency balanced flue type when my previous boiler failed. That was about 15 years ago.

Rules regarding replacement boilers changed in 2018. Fitting a "lower efficiency" boiler today would appear not to an option.

I would not go for a combi boiler either - system boilers are still available. I don't know of anyone who has a combi boiler that has not had reliabilty issues at some point.

Replacement boiler grants are available in some cases that may help reduce the financial pain ?

Nigel B.

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Plagiarised from my post at 14:38:08, then?

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I would be interested in why the boiler has failed like this. Corrosion would be my guess, possibly fatigue?

I think welding, by a competent welder (coded or whatever its called these days), would be an entirely satisfactory repair if the cause of failure can be determined and insurance companies can be convinced. The cost of this and getting the "gasman" to remove, strip, assemble and re-install the boiler may well cost as much as a new boiler.

Some 35 years ago I installed a "Trisave" condensing boiler. It split its heat exchanger (aluminium) clean in half. Only noticed when the cover was removed for servicing. A call to the manufacturer said not to worry, they all do that. They are welded together to make machining and initial assembly easier, no risk of a leak.

John

I've been in this house nearly 40 years, I'm on my second combi boiler and it's still going strong. The only problem with this latest has been a failed sensor, the flashing light on the front tells you which one, but don't trust any old plumber, they need a bit more thinking about.