Hearthstone crack repair

[ajamison]

I have a hearthstone homestead. It was overfired a few years due to a slightly ajar ash door. Stove has worked great since then but I recently discovered these 2 cracks on the back of the stove (the one to the left is easier to see in the picture but there is also a smaller one to the right)
1) can they be sealed with stove cement?
2) is it safe to run the stove with these cracks?

 

[begreen]

That's not a good place to have a failure. Cement won't be anything but temporary. If that piece falls out or opens up when the stove is fully loaded and burning, it could present a serious issue. The best solution is to replace the stove back.