Is there any other reason not to set up a storage tank directly to the wood boiler in a closed system other than needing a large expansion tank? There would definitely be less loss of efficiency in the system and it seems to me it would be a lot less complicated than using multiple heat exchangers. I presently use a 110 gal. tank as a dump zone in case of overheating on warm days. My wood boiler is a bit small for my big old house so it rarely overheats. I would like to build a larger tank for storage and maybe connect directly to the boiler. Any thoughts?