I have it setup with an exchanger for my domestic water and another exchanger above my furnace, if that's what you are asking? It works very well for me. The exchanger for the furnace is usually $100-200 depending on the size of your plenum and heating needs, and a plate heat exchanger for the domestic water is usually in the same range, again depending on your needs. Sidearm exchangers are another option and the copper ones are a bit cheaper, while the stainless ones are in the same range as the plates. I prefer a plate myself, as it's more instantaneous while a sidearm isn't so quick to recover