Well, file this under "problems to have" I guess. With my schedule, storage capacity etc. my oil furnace hasn't had to come on since about September. I've turned it on a couple times after I made some tweaks to the system and had to get some air out, but that's about it. I leave it on, and the controller is in "auto backup', but storage has never been cold enough for it to fire. The aquastat on the backup (tankless coil oil furnace) stays at about 67-70f. There have been no leaks or anything. So, what's the consensus on running it and how often?