That is a good suggestion. I never wait until the stove top is at a set temp, and certainly not as high as 600F! 400F is much safer. Actually, from a cold start I have started dropping the air control when the stove top is as low as 250F. It takes time to get the outside steel hot, while it could already be very hot in the firebox. vasten, it sounds like part of your problem is the house is losing heat rapidly. That is where I'd focus attention. Fixing heat loss will pay back a lot faster than replacing the stove.