Crack in Hearthstone cast iron frame

Hello all,
Thought I would ask for advice about a problem we just had with our Hearthstone Heritage wood stove. When the stove was warming up the other morning (flue temp about 400F) I could hear "typical" tink-tink-tink expanding metal sounds I'm used to with stoves, except this time the pitch was higher and quite rapid. Then the stove made a quite loud pop. I was near the stove and checked it out but could find not anything unusual. After I left for work 1 hour later my wife heard another loud bang again while the stove was on low burn. We then saw the crack in the lower cast iron frame at the back, extending all the way through to the ash grate in the center of the stove! I was totally shocked!

We did buy the stove second hand and therefore have no help from Heathstone except an offer of $400 replacement frame part or $900 repair (+ shipping). They said it must be from overfiring, but we are very careful with the stove and have put 4 cords of wood through it in 2 seasons without issue (I run 2 thermometers on the stone and in the flue). the stove is also in very good condition without any cracks in the stone except a 1" across the corner of a stone on the back. Not to write a book here, but I notice the crack widens (almost 1/4") when the stove is hot, and narrows to nothing when cool. I notice also the cast iron at the back heats up the fastest when the stove is warming. I'm not sure replacing the frame will cure the problem. I have a friend who can weld cast iron... maybe that's the best approach?

Appreciate any advice what may of happened here or similar experience you folks had.
-woodchopper

here are a few pics

Looks like a bad casting. I'm not a metallurgic science expert, but the jagged surface profile and the way the crack propagated leads me to believe that.

That is a heavy stove. Not easy to move around when bringing in and out of the house. Is it possible that in the process of bringing this monster in the house it was dropped down hard. Could have started as a small crack.Or whom ever you bought it from might have dropped it.Then over time from the heat it finally gave out.

Woodchopper:

Did you send those pictures to Hearthstone? How old is the stove? I would have hoped if the stove was only a few years old Hearthstone would have stepped up and done a little better.

Welcome to the forum, sorry it is on such a sad and costly note. I would go with your friend welding it if he can truly do it right. It would probably be a lot cheaper.

Probably a mounting point for the rear shield or OAK.. I know both of my 'stones had/have mounting points cast/threaded in..

thanks for the input guys... the stove is 2006 year, and I gave the pics to the dealer who I assume gave to Heathstone. I too thought they would do a bit better considering all cast iron is lifetime warranty. I have a friend whose Jotul cracked sounded similar to mine and he said Jotul came in and replaced it but he was the original owner ..
I think I'll go for the welding idea..

thanks for the site tonnes of info here, helped me find the stove which I still love

Stoveguy, we handled 'er with care on our part but don't know about the original owner...
Brotherbart, I think those holes are for a rear heat shield?