[ars]

> if your house were kept colder, then you'd lose less energy to the outside.

Yes, but I can't let it cool very far, so it's only a small energy saving.

> How does this compare to the efficiency gain by running your more efficient flame?

The boiler can be up to 98.6% efficient at low flame, going down to 86% at full flame.

And after experimenting it always ended up at full flame when trying to rewarm a house.

> Have you calculated or measured that you actually save energy overall?

I tried, but I couldn't, winters are just so variable. I even emailed the EPA asking if they had research data, but they didn't.