We live in Portland OR, and have a 275 gallon tank to heat a 1000 square foot house. We usually keep the thermostat at 64° when no one is home, and I put it at 66° or 68° in the evening. Once the weather gets nice, May or June, it pretty much never comes on until September or October.

We filled up last year in January and again in September, but I know it wasn't empty yet. Since September, we're already down to only 1/4 tank left, so 5 months it took? Well, I guess that's about right, we fill up twice a year. This next fill up tomorrow will last us another 8 or 9 months.

We spent around $500 each fill up, so around $80 a month. We just put it aside with our mortage every month so when it comes time to do it, the money is already there.

I do run a space heater sometimes in our back room, but only because the floor is tiled and our dog door is there, so it's a little drafty. Other than that, the house stays pretty cozy when we need it to be. At night, we prefer to be a little cold, our two dogs snuggle up in bed with us, they're our little heaters!