Here is a photo of a 50+ year cast iron old hot water boiler with the face plate removed. Occaisionally you’ll see a unit like this in a home. Few home inspectors in this area understand hot water heat. Although boilers like this can have 50 year life spans, they often lack proper controls and maintenance. A major drawback is that central air conditioning cannot be installed without a seperate air handler and ductwork which is a huge expense. Ultimately these factors should be reflected in the value of the home. Central air conditioning is almost a given in 2007 where it didn’t exist in 1955.