Kerosene Scent in House

Its most likely not pipes but a single pipe. The reason I asked was in case there might have been a leaking pipe inside. You didnt address my suggestion about getting installer back.

Can you post a pic of the boiler including nearby door and windows?

Can you also post the results from the combustion test at commissioning time?

One cause could be a slight weep from the tank pipe bend. This would allow oil to flow along that plastic sleeve and appear inside the house.

That was my reason for asking that pipework question earlier.

In this case there might not be any oil visible inside. The close proximity of those heating pipes might cause any oil to evaporate. That would exaggerate the smell and hide the evidence. Best to be certain of no leak at the tank side and that inside fitting you mentioned in a recent post.

Flared fittigs would be best, but not many use them. Next best would be those inserts that oftech recommend, but are scarcer than hens teeth. I gave up searching in plumbing supplies for them.

Thanks for that Jim. I'll probably not bother then. Happy Christmas to you and yours. 👨‍🚀🕊️🍹⛄️❄️