Dear forumites, I live in a condo (one of 3 units in an old house) in the Northeast. We currently have steam heat using oil. We have one tank and one boiler, for the whole house, which is probably 10 years old and in decent shape. The units share the cost of the heat. We're considering changing to gas because of high oil prices, environmental concerns, and U.S. oil-dependency concerns. We can get a new high efficiency gas boiler from our gas company for $799 (or a less efficient for $499). We had an installation contractor come out and he said it would make more sense (cost wise) to stick with one boiler for all 3 units rather than install separate boilers for each unit. He gave a very rough estimate of around $5,000 for the conversion, including the cost of a $799 boiler (I should mention we have a gas line to the house and run our hot water heaters and our stoves on gas.) He also said, given the age of the boiler, that we could put in a conversion burner which would be cheaper but since he doesn't do those he didn't offer any more information. My question is this: should we just add a conversion burner or should we replace the boiler? I understand that using a conversion burner will result in a loss of efficiency but is it safe to do so? It seems to me that the boiler was made to work with oil. We're interested in not just spending less on fuel this winter but also in being environmentally responsible. Is an oil boiler with a gas conversion burner likely to emit more pollution? Thanks for any advice!

I'll focus on the HVAC side since I don't know much about direct vent hot water tanks. The quote provides enough information about what they plan to do which gives me a good feeling about this installer. However since you are providing the equipment, the quote is high in my opinion. Sounds like they are still quoting the job as if they provided it and marked it up. I think it can come down at least $5k. Who is providing high voltage power to these units, or is this an additional cost paid to another contractor? Also to clarify, will there be multiple returns on the first floor as well or one central return in the living room? I would clarify with the dealer about the ductwork system. By the quote it sounds like it is all hard metal, with no flex duct even in the attic where it is common. If this is the case, great. This could account for why the quote is on the higher end. I would strongly consider upgrading to the 15 SEER condensers if the unit price increase is not more than a couple hundred per unit. They should be quieter and are overall nicer units in my opinion even if they have the same cabinet. Another upgrade to look into is a high efficiency media filter for each unit. They typically get replaced every 6 months or in some cases up to a year, and they provide better filtration of the air and hence protection of the equipment. These may add a couple hundred per unit installation.

I have no experience with this either - but I do have experience with gas furnaces. I can't imagine a conversion that would be the right answer. New gas furnaces are easily 92-95% with condensing secondary heat exchangers, outside air intake, venting through PVC and ECM blower motors. All of those things are great to have. Venting through PVC solves venting issues (lining a masonry chimney, for example). Outside air intake reduces air infiltration. ECM blower motors ramp up slowly and use less electricity both in the winter and in the summer w/AC. You will give up a lot trying to do a conversion - and I can't imagine you would save much money.

I’d speak with a real estate agent regarding what type of system buyers prefer to see and what they will walk away from. I’m in a different market from yours. I’ve heard of realtors not wanting to take on any property that has oil due to the problems, liabilities and buyers not wanting oil. That said, in your position if doing nothing is a viable option, that’s what I would do and deal with it in a negotiated sale price. The other discussion to have with a real estate agent is the likelihood of a purchaser wanting to have a soil test performed to determine if there ever was an oil leak, a lender might require this as well. Depending where you live, if the answer is yes then you might have BIG problems that are expensive and would delay the sale of your property. Getting rid of the oil system and installing gas would likely negate that situation altogether in that oil would not be seen at all. Have a conversation with a real estate agent and a building inspector concerning oil, particularly oil tanks, speak with an insurance broker as well. You might even consider having your own inspection done on your property that you can hand to a real estate agent or a perspective buyer. Being in the HVAC business I have an entire file going back many years just on oil problems with many pictures of excavations that would scare the HELL out of most people. IMPO SR