This sounds like it was initially defective, just took a few years to rear it's ugly head. We don't have that same kettle anymore, we've switched to the Megapot 1.2. Give us a call or shoot us an email, we can hook you up with a replacement. Just tell them that Gabe from CS sent you.
There's a couple things to know first, if you have a false bottom from this pot, it won't fit our current generation 15 gallon Megapot, but it will fit our current 20 gallon Megapot. We might have to charge you a few bucks if you wanted to go the route of a 20 gallon pot. Anyways, give us a ring and we'll work it out.
-Gabe from Northern Brewer