I have an older Jotul 3DVII that I got used from a friend of mine this fall. I had someone install it as far as putting in a liner and the local fuel place installed a propane tank and line. The stove lights but does not seem to heat the space very much even with the doors closed; roughly 13x13 . There are two outer walls but they are both thick brick so not too much loss there. I had the fuel company check the regulator outside today and they said it was fine (didn't give me details). My friend also came and took out the burner tubes and tried to blow out the jet; it didn't seem to change things much. You can feel it giving off some heat but you can leave it on all evening with the doors closed and it gets slightly warmer than the other rooms; plus it has a vent from the oil hot air furnace so it's getting some heat from that as well. Thoughts?