Yikes C.Ann, that is not fun.
Have you considered on maybe getting one of those fireplace wall units? no they do not need a chimeney for that and they are quite efficient, also if you loose power since they run on propane you don't loose heat. Putting in a new boiler can be quite costly, I know because when we put ours five years ago , the boiler alone was over $2000 and we were doing the instalation ourselves, we did the heat/hot water baseboard heat around all house, the guy who saw it after that said that if we had someone come out and do it , it would have cost us over $10.000 , we did it for a bit over $3000 with all materials.