I have a proposal fro a high-effiency, gas-fired Lochinvar boiler (with indirect HW) that will be used for radiant floor heat. The proposal includes a Boiler Buddy tank that adds mass to the system to prevent short cycling.

My questions are how much does this increase the cost of the system and what’s the the payback? Also, can a system be designed/installed so this component could be added at a later date?   

Thanks,

Richard