My oil delivery service company replaced an our old tank in 2014 and a few years later a mainenance guy said the vent was improperly inverted and told me it would be fine long as the tank isn't overfilled. It's been that way until now with no problem. But now the very old combi-boiler will be replaced by the same company. Today I picked up the permit from Code Enforcement and he told me there'd be an inspection after the installation. SO I'm sitting here wondering what will happen if the code officer sees the screwy tank vent and won't approve the installation of the oil tank, retrospectively. For whatever reason seems it was never inspected. This is a BIG oil services company, not a freelance job. I think they screwed up by not installing a horzontal tank originally instead of what the installed, a vertical tank with very little headroom. Took the easy route after bringing the wrong tank. One question is if the tank has to be replaced, should they have to pay for the mistake? This is kind of a legal question. Anyone have an opinion? Thanks. Here's vent situation photo.