In the past our heating bill for natural gas hovered around $350 per month to just take the chill out of the air in order to heat this home during the winter months, this doesn't mean being toasty warm, it just means we aren't freezing our tooshies. If I spent $500 per month on natural gas then this place would probably be above 70. As an experiment, I wanted to see if I could actually heat this place solely on wood. It was a challenge to always keep a ready wood supply handy but succeeded in doing so. Our very first heating bill arrived last month from our friendly natural gas company now that we're solely heating with wood using our newly installed Quad insert and to my amazement our natural gas bill was a meager $28.71 . Can you say I sure can, that's what it is in the summer months when we're just heating water for dishes and showers. I figure at this rate in 5 years I'll be at the break even point of this wood burning investment and hope for many more wood heating years to come.