I need to replace the oil-fired boiler for my 2-pipe steam system. In addition, I have a sunroom that has radiant heat, which uses a gas hot water tank that is leaking. The radiant system is expensive to run (like, $150 a month for the gas!) So since I need a new boiler, I want to consider options for the radiant other than just replacing the hot water tank. One contractor is pushing to convert from steam to hot water, and run the whole system--radiators and radiant, off that. I'm reluctant because I'm afraid of leaks (house is 80 years old) and complications that I just know will pop up. The other contractor I consulted recommended a new steam boiler with a coil in it--the water for the radiant system would flow through the coil and be heated that way; a control of some sort would keep the water for the radiant at a low enough temperature. Typically, my boiler only runs early in the morning and then again in the evening, unless it's super cold out, but the radiant runs pretty much constantly, so it seems to me that this would be a poor combination. The contractor says the water in the boiler will remain hot for a long time even after it stops making steam, and if it needs to fire up again just for the radiant, it won't have to get hot enough to make steam, so it wouldn't be as inefficient as it sounds. I'd appreciate any and all informed opinions on these options--it's so frustrating to have to make big-ticket decisions like this when you're not remotely an expert!