While retrofitting can be done, it's often not very cost effective unless you can DIY all of the labor. It's done for comfort, at a premium, rather than basic home heating. Talk to a few specialists to get some quotes to compare.

I can't speak to the in-floor radiation, although it sounds marvelous. We just did a retrofit of our 1910 whole-house hot water heat using the original castiron radiators. To our surprise and continuing delight, a new German high-efficiency direct-vent boiler with Triangle hot water heater has saved us over 50% each month over our old bills. We now have tons of heat, and we're in Maine. Do make sure that your original cast-iron radiators aren't repipable before replacing them? They don't make 'em like that any more, etc etc.

For the addition, that's always tough. We removed a radiator in our kitchen, but made up for it a wee bit by relocating the laundry room directly below it in the basement. I'd kill for in-floor in my kitchen, but it is indeed terribly expensive.

Up to you to decide what the priority is -- it certainly would be a very understandable outlay in cold climates like ours, and potentially could be paid for by the expected savings with the new boiler?

Triangle boiler with their attached water heater is what we are looking at. So, it is very encouraging to hear about the increased efficiency and lower bills you are seeing. Did you get the Buderus boiler, or did I misread and you have Triangle for both units? We are in Minnesota so definitely similar climates.

Saving our radiators is not possible. It was about 20 below here when our heat went out, and all of the radiators froze. When the ice formed and expanded, it caused all of the radiators to crack on multiple seams. That is why we are looking at different alternatives.

Thanks for the input.

I agree that in-floor may not be best for whole-house heating. We have it in a few rooms, and while it has advantages it also has disadvantages. The biggest one for me is that you cannot change the temperature of rooms quickly with it. Once it get up to heat, it stays there, so you cannot for example let the bedroom be cool at night but warm in the morning. And it's best for closed-off rooms, at least in my experience.

We have the Buderus furnace with baseboard heating with several zones. It is very responsive, but with our well water (very hard, lots of minerals) we have to be absolutely sure to have it serviced every fall. It provides the hot water for the taps, too, and responds quickly when we need more.

We had gas heat with baseboards when we lived in northern PA It got as hot as you wanted it to get. I sure do miss it.

In floor heat uses a max boiler water temperature that is lower than with radiators/baseboard of any type. Make sure your contractor knows what he's doing. For a house that has both in floor and radiators/baseboard of any type, a mixing valve in the in floor loop is used to mix hot boiler water with return water from the radiator/baseboard loop to bring the temp down. You can google for more info on mixed systems.

You could put the kitchen on its own zone and thermostat. Based on what you had before, you can calculate the BTU's/hour delivered by the baseboard and make sure the new system delivers more. If you have regular kitchen cabinets, you can install one or more kickspace heaters. I installed a Smith's Environmental unit in my rear entryway which I'm very happy with. The heavy weight in the industry seems to be Beacon-Morris.

hi Needinfo,
Our boiler is a high efficiency Vitodens by Viesmann, it's German.

Works brilliantly with the Triangle water heater and it's heated our 2400sft old house with no problem through the worst winter in years.

My sympathies on the loss of the original radiators. We were lucky enough to inherit the originals that, even better, have never been painted or otherwise messed with.

Good luck choosing!

We are getting closer to deciding what we will go with as far as replacement heating (and thank goodness that it is warming up outside so we don't have to make a hasty decision without time to thoroughly investigate all of the options),

I appreciate all of the firsthand feedback people have been able to give me about their own experiences. We are looking at a system with four separate zones to address the differing needs in different parts of the house.