Ok, here is the deal... I have been monitoring oil useage since December of 2006, and then in 2008 we got our insert. (Did a search on this, but came up empty...I know I saw a similar post a while back) I currently have an oil fired boiler, with one of those tankless units above the boiler. I have seen a great decrease in oil usage during the winter months due to the insert....gallons per day were appx 3.4 prior to the insert, and we now use about 1.8/day during the same winter months....not 24/7 burners. If I look at my oil useage during the non winter months....say early May through the end of Oct, I am using about 1 gallon per day...so at $2.80 a gallon I am spending about $84/month for just hot water when the heat is off....maybe thats not that much/month? Just seems like a lot to me. Current electricity costs are 15.1cents/kwh...so I guess I am asking those folks that heat water with electric what their normal useage would be? Current household is a party of 5..2 adults, 3 kids....all boys....no one takes a long shower....wash all clothing in cold water. Does it make sense to just go to a decent Electric Hot Water Heater? (Assuming oil prices increase at the same rate as electricity) Never owned/used electric hot water before, so I have no idea on what a typical monthly useage might be. Mods, feel free to post in the green room if it belongs there.