Here is one big reason gas-fired units are displacing oil-fired ones.
This Slant/Fin Liberty steamer, operating a Kriebel system, had been "serviced" every year, not sure what they actually did but it can't have been any more than a rag-and-tag (we found the tag) that lasted a half-hour at most. The fuel bills were excessive, and the oil company was no help to the owners. They called us to fix some system-balance issues, which we did, so we got this part of the work too. The story ends, like many, many others, with a switch from oil to gas- this time, with a Carlin EZ-Gas burner.
Soot and sulfur accumulations do a great job of keeping the heat from reaching the boiler water. If a modern oil burner is installed, adjusted and maintained properly, it will not generate soot. The amount of sulfur in this boiler tells us it hasn't had proper service since before they started lowering sulfur levels in fuel oil.
This is only the latest one we've seen in this condition. I like to see competition as much as anyone, but these guys aren't even trying. It's like taking candy from a baby!
There are some great oil guys on this board and several others, who would never dream of leaving a boiler in this condition. If you are reading this and you have oil-fired equipment, these great oil guys are the ones you need. If you are reading this and you own or manage an oil-heat company, and this is how your alleged "techs" treat your customers' equipment, they will fire your company like this family did. Guaranteed.
On this job, we also changed from a float-type low-water cutoff to a probe-type, and will change the Pressuretrol to a Vaporstat next time we're there.