Help,
I just bought a home in July 2006, the home is built 1976. It has a 3 ton Say and night unit, I had it serviced in September for the cold weather. The Tech found a 2" X 8" crack in the heat exchange. I have home warranty but they refuse to fix it. HSA would not recommend them to anyone. I can't find a web a web sit for them, nor can I find out if any recalls have been call on the unit. Also is it cheaper to buy new unit or have repaired.

I think you should have posted this under legal. You paid for a warranty, and they are refusing to take care of a major life threatening problem?

A lot of repair/replace depends on how old the unit is. If it is the original 76 furnace, don't even consider repairing it. Put in at least a new 80% efficient unit, maybe higher depending on what the installer suggests. Ten years ago I was told 90% units cost more in maintenance than they saved. Could be different now. Gas is up and likely continuing to go up.

I always suggest replacement over a new heat exchanger and there are many reasons. The homebuyers warranty needs to fix this problem for you, read your warranty closely. They will usually do the repair, you should consider doing the replacement if you can afford to pay the difference.