You were given good advice there Sheriff, about bringing the stove up to temp slowly. Mine had been going for nearly 24hrs when it cracked, and was well up to temp, so I don't think it would have been that. The intermittent use theory is interesting. Mine has been getting fired up every weekend since November, but during the week it will lie cold, especially last week when the temp dropped to below freezing, and may have dampened the cast, or some of the rust inbetween the plates, causing them to pop the plate.