I am getting quotes to replace an existing conventional Williamson forced hot air gas furnace and Carrier air conditioner in Connecticut. Most contractors are recommending standard furnaces and air conditioners such as the Carrier Infinity series. One contractor is suggesting a gas fired Triangle Tube Prestige boiler. This boiler will feed some sort of a radiator installed into the ductwork above the air handler. A standard air conditioner could be installed above that. He claims that the boiler will be more efficient than a conventional high efficiency gas furnace. In addition, the boiler could feed a hot water heater and improve the efficiency of that as well.
I haven't found any discussion of using a boiler to heat a forced hot air system. Does anyone have any experience in this? Is it practical? Is a boiler more or less prone to failure than a condensing high efficency furnace such as Carrier Infinity or Trane XV?