im looking at buyin a house with water heat it has a boiler with radiators is there any advantages or disadvantages against forced air? how much would it cost to convert to forced air just a ball park figure (900sq home)
i know that adding central air is difficult

I can't speak to how much it would be to convert, but I know that central air is WAY more efficient that water heating. It'* going to be in your best interest to convert, especially if you have the house for a decent amount of time. Plus should add resale value.

central air is cooling

I meant central air for heating, like with a furnace and such. I guess it'* forced air, either way that'* what I meant.

I have no idea how much it would cost to put in duct work. But, like you said, it could be difficult depending on the design of the house. I have an old house with a boiler and steam heat (radiators). I think hot water is a good system as you could "zone" the system to various parts of the house. So, you don't have to heat the entire house at the same temperature. I'm just curious why you think that forced hot air is the way to go.

well im just curious i know that zone heating is very cool and boilers outlast a F/A Furnace any day with proper maintence
but just curious on what kind of maintence is needed for these things also

forced air is the new thing i guess

My mother'* house had hot water baseboard heat. The pluses are it'* very quiet & clean. I'm sure modern boilers are just as efficient as modern forced air systems. The only drawbacks are adding air conditioning & you can't let the house get so cold that the pipes could freeze. Freezing isn't normally a problem but could be if the power went out for a long time or if one zone is turned down too low. Pretty much maintenance free but every now & then too much air gets into the system & the pipes will bang.

I have a boiler with base board pipes and I like it alot better then my old house that had a furnace. When it fires up for the first time it'* cold, it sounds like a waterfall is in your wall. Freaked me out the first time, thought a pipe blew.

Well around here the furnace is on 8 or 9 months out of the year, so maybe you could be ok with water heating in a more temperate climate.

Thats funny. In Detroit, it'* on 6-9 months. Depends on Mother Natures menstrul(sp?) cycle.