Oil Boiler Kettling , now Leaking!

[alan8376]

My oil boiler, a Boulter Camray was kettling, so I put some Sentinel in to clean out any build up of scale etc in the heat exchanger.

One month on, I now find the exchanger is leaking! (not sure if it was before, as I have just found water under the lino). Anyway, as the boiler is 12 yrs old I decided to strip it out to find the cause!

I have found 2 stress cracks on the exchanger at the bottom corners, they are near the welds. I suspect they may have been weaknesses when built??? There is NO sign of corrosion inside at all. The welds themselves are looking fine! I am tempted to cut the cracked sections out to investigate!

Any comments on the cause anyone?

 

[Agile]

You did not say which model of boiler or which Sentinel product.

I assume its a c.i. heat exchanger.

The cracks are probably caused by thermal stress resulting from lime scaling giving poor heat transfer. The product you introduced may well have removed scaling which has been blocking those cracks for some time.

Hopefully you will now replace the boiler? Although there are some firms who will try to weld c.i.

If its only cracked on the outside you might even do a temporary repair with epoxy but usually the cracking is on the flame side.

Tony

 

[alan8376]

The boiler is a Camray 40/50 Camray 3.

The Sentinal product was X200.

What is a c.i.?

Thanks Alan

PS. New boiler will follow

 

[Agile]

c.i. = cast iron

 

[alan8376]

Sorry forgot to mention it is a steel one. Saying that! The exchanger still looks brand new in and out..

The cracks are where the base plate is welded to the exchanger

 

[Nixt]

c.i. = cast iron

It'll be welded mild steel water jacket Agile. There were cast iron models such as Potterton BOA but 12 year old Camray is likely to be the 3 model for which jackets are obsolete.

 

[Agile]

Is that mild steel?

If so then it can be welded!

Tony

 

[alan8376]

Yes, I presume mild steel!

 

[gremlin16]

If so then it can be welded!

Stick with your gas boilers.

Cracked oil boilers are due to years of neglect. Not even a proficient welder would atempt to weld a rust bucket !

have found 2 stress cracks on the exchanger at the bottom corners, they are near the welds. I suspect they may have been weaknesses when built??? There is NO sign of corrosion inside at all. The welds themselves are looking fine! I am tempted to cut the cracked sections out to investigate!

How can you see into the bottom of HX.
Being 12 year old the boiler is bound to have carp on bottom[/quote]

 

[simond]

You suspect it might have been a weakness in the boiler 12 years ago?

12 years ago?

Are you having a laugh?

By all means cut your boiler into slices, I for one won't be able to sleep tonight in anticipation of what you might find.

Do post back.

 

[alan8376]

Message for Simon,

The boiler has been serviced every year since new! It had Fernox Inhibitor added on fitting.

When I get hold of a large enough angle grinder I will take the corner out of the H.E. for a closer look. I am as interested as you are!

From experience, what do you expect me to find on the inside? Will it be full of crude and worn thin and scaled? Or, will it be a clean crack caused by the kettling?

Alan

 

[Agile]

Mild steel is much less subject to thermal stress cracking than cast iron.

If the crack is adjacent to the base plate then I would almost wonder if its resulting from a weld stress.

Tony

 

[simond]

This thread is actually rather funny, please keep it up.

Have you considered a laser cutter, so none of the evidence is adversely affected by heat?

 

[alan8376]

Simon,

If and when I cut the corner off the H.E. I will be more than willing to send you the piece for a comment!

Please send me your postal address?

Alan

 

[wilhelm]

If youve got time,to prat around ,then weld it up. Ive seen it done once on an old camray wall hung boiler. That worked.

But if something is sh£gged, its usually sh£gged , and we move on

I had to buy a colour tv last month ffs.