Hi Brewster -- many thanks for the information and possible contact. Looking at a house that we may put a bid on and it's oil -- boiler is old and oversized so the rough cost certainly helps. Of course, the house has an underground tank as well. Given the age of the boiler, I'm not discounting that there may be an issue with the oil tank as well. Not sure how well they are able to test for leaks without really pulling it up. My neighbor just has his tank removed - it had a leak -- ended up costing $18,000. So, we'll see. Appreciate the offer on your guy.

Sorry, but it depends on what you have now. I have no idea about central systems, but if you have a relatively young steam boiler, it's pretty simple to replace the burner with a gas one. If it's older, oversized (common) or both, it's better to replace the whole thing. I did the latter and it cost about $7k. I don't know about hot water oil boilers, but I'll bet conversion is possible. Pm me if you want the contractor, he's good guy, uses numbers rather than seat of the pants. I'll ask him if he's OK with my posting his info.

Any estimated (better yet, actual) costs for converting from oil to gas, including all related costs, would be appreciated. Any recommendations regarding firms to do the work?
Not sure if PSE&G does this -- but I know they tend to just use local plumbers for some work and I guess they then tack on a surcharge to make some money.
Many thanks!