Link up those boilers and loads for the best results.
I just finished reading about a "dream house" built to showcase the very best in domestic luxury and technology. The owner wisely selected hydronics to supply radiant floor heating, snowmelting and pool heating.
According to the article, the system used a 400,000 Btu/hr. boiler for pool heating, another 200,000 Btu/hr. boiler for radiant floor heating, and a third 600,000 Btu/hr. boiler for snowmelting. All these boilers were located in the same mechanical room, but operated as three independent systems.