@Last Plumber can you tell me about hydrogen sulphide. I know what it is and it’s effects on people and the environment but unsure of its relationship to natural gas. Is it found in the gas and not removed while being refining or is it a POC?
I'm no Chemist so I don't know that much about it. It is found in Nat Gas but there is not much left after the refining process as you probably know. They also add an odour to it here so we can smell it. I don't think we would smell the small amount of H2S over that to be honest.
It does effect the inside of copper tube by reacting and producing copper Sulphide? as I said, not a chemist but I think that's right. Feel free to correct me if I'm wrong.
When I was thinking about the smell of rotten eggs in relation to this boiler above, I was thinking of the times I have come across that pungent smell from boilers I have worked on (inside them though, never outside). I have noticed it before but only in certain sections. I have noticed it with solid fuel stoves, or oil Boilers, less so for natural gas but I have noticed it on opening a sump which has rarely been cleaned out and full of deposits. That's why I was thinking of leaking heat exchanger sumps or condensate drains?
I think it is bacterial reduction of Sulphur that releases the Gas.
My thought was that if it is coming from inside the boiler combustion chamber, flue, sump or condensate pipe (before the trap), it could also have POC's with it.
It may well not be H2S from the Boiler. It could be a dead rat or a dead bird up his chimney or stagnant water but it reads like it is only there when the boiler is on.
Does my thinking make sense?