I am still going around and around between an EKO 25 and a Tarm Solo Plus 30 for the new house I am building. Either way, I am interested in storage. Where can I purchase a large storage vessel? Also, If I heat my hot water with a direct coil in this resevoir, what are good options for backup hot water? We will often be away for the weekend, and I am considering a direct vent propane boiler as backup. What is a good way to supply backup hot water? I would not want the propane unit heating the resevoir. I may not purchase the backup unit at this time. My hope is that I could keep the house at 50 degrees for a few days on the resevoir when we are away. I intend to do all of the installation myself. I liked the specs on the Econoburn unit, but they won't even give me a quote since I am not a licensed contractor. This will all be quite a challenge...I see the most difficult part being the lack of a parts supplier in my driveway...there are a lot of little pieces to plan for.