Hairline crack in CH boiler

[Alan Wood 4Participant @alanwood4]

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

[Alan Wood 4Participant @alanwood4]

Short term repair solution

[Alan Waddington 2Participant @alanwaddington2]

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.

[Grindstone CowboyParticipant @grindstonecowboy]

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

[Robert Atkinson 2Participant @robertatkinson2]

Posted by Alan Wood 4 on 08/12/2020 19:54:56:

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

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

[J HancockParticipant @jhancock95746]

Don't even think about it.

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

[Former MemberParticipant @formermember12892]

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[Dave HalfordParticipant @davehalford22513]

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.

[not done it yetParticipant @notdoneityet]

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.

[Dave HalfordParticipant @davehalford22513]

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

[Former MemberParticipant @formermember12892]

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[Former MemberParticipant @formermember12892]

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[not done it yetParticipant @notdoneityet]

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

[not done it yetParticipant @notdoneityet]

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.

[Ex contributorParticipant @mgnbuk]

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.

[Former MemberParticipant @formermember12892]

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[not done it yetParticipant @notdoneityet]

Posted by br on 09/12/2020 14:44:36:

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.

My point exactly

The non insurance employed members seem to know better.

br

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

[Former MemberParticipant @formermember12892]

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[Former MemberParticipant @formermember12892]

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[John MCParticipant @johnmc39344]

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

[duncan webster 1Participant @duncanwebster1]

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.

[Brian WoodParticipant @brianwood45127]

I think everyone is overlooking the question that Alan Wood posed at the start of this thread.

He wanted to know is there is a short term solution that will see the old boiler through Christmas, now only a matter of days away. It is most unlikely to fail catastrophically in that short time and having nursed an old boiler through to the point where it would no longer light up I would back a leak sealing route for the short period it is needed to hold things together .

He clearly intends to replace it anyway and trying to find a boiler engineer free to make the change in an emergency is usually difficult. .

He should though be making arrangements now for a boiler change and getting the man booked up to do the job. That way any insurance claim for collateral damage should stand up as all reasonable steps will have been taken having discovered the problem

Regards Brian ..

[Dave HalfordParticipant @davehalford22513]

Posted by br on 09/12/2020 14:40:49:

Leak sealer rings a bell — I think I saw it in HALFORDS the other day. ?

 

br

Edited By br on 09/12/2020 14:41:54

Wrong stuff

Obviously central heating leak sealer is required.

As mentioned in the third (now second) post

Edited By Dave Halford on 09/12/2020 17:40:24

[john fletcher 1Participant @johnfletcher1]

Some 70 or more years ago when I was a boy, our solid fuel boiler cracked and leaked. Dad being a handy type, drilled and tapped a parallel series of holes, the length of the crack. He then made a patch using a length of copper to fit, and a rubber gasket. We soon had the heating back on. A similar arrangement might be the way forward at minimal cost. John

[Alan Wood 4Participant @alanwood4]

Thank you everyone for the opinions expressed which are noted and appreciated.

I have no idea why the crack has occurred but it does only emit a fine spray when the boiler is running. Given its age it is past its sell by date and I will proceed on the replacement path.

Alan

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