We are having nighttime temps. in the mid 30s to mid 40s here in WV most nights, and I'm still running my water temp at 135 max with no issues. The water temp goes down to 115 before the draft fan kicks on. I'm heating my house and garage, and loading the stove "light" twice a day, or fill it and not have to worry with it for a day or so. If I have a little smoke,,, I don't have to worry about it. I think keeping the water temp low should save some wood.