shagy said:I am confused! Where is combustion efficiency listed on the EPA site? If a indoor boiler had won that award it would have been well received. I find it interesting the forum is so against outside boilers even with all the improvements they have made with gasers. Some do not even consider any of these gasers. Others do not believe the EPA's listings but at least they have a listing. The inside gasers have NO public listing of efficiency's but the lord has blessed them. I find the improvements in both indoor and outdoor boilers fascinating. I would think these improvements would please more people.