Hot Air hispec j40 All aspects of plumbing questions and answers, help, tips and information

[ella's boy]

I have a JS Hispec J40 Heating system. I have been told that I need a new Heat exchanger for it.
Being totally ignorant can anyone tell me if this is only for the water side as I have a seperate method of heating water and secondly if the weld on the body is leaking gas can this be repaired?

[/list]

[htg engineer]

You will have two heat exchangers, on for heating and one for water. You need to establish which one needs replacing.

If it's the one for the heating side - this cannot be repaired, as the tiniest crack can lead to fumes being blown throughout the property by the fan as the fumes will be drawn through the crack from the combustion chamber.

htg

[ella's boy]

Thank you for your response.
It is for the heating side as you suggested.
My true question now is, I am being told it is leaking from the weld/seam.
Why can the not be repaired by welding as it is not a pressure vessel?

[htg engineer]

As i've already said the tiniest crack/gap/hole and fumes can be drawn through the heat-ex by the fan and blown throughout the house including the bedrooms - if this happens you will not wake up.

Is it worth it ? how would you test/check the weld was 100% sound ? they will be checked at manufacturing stage.

If it was a pressure vessel I would say go for it - weld it and save a few quid - but the pressure vessel wouldn't kill you (unless someone hit you with it) you may get wet though. Whereas a dodgy weld on a warm air heat-exchanger could kill you
.
htg

[ella's boy]

Enough said...
Many thanks for your answer.
Looks like I will wake up, but with a large hole in my pocket!!!

Would you know where's best to buy from?

[htg engineer]

Yes but you're looking at around about £400 excluding fitting.


http://www.e-gas-boiler-spare-parts.co. ... SPEC%20J40


htg