Like I said, a completely blocked line, especially with no leakage, is not typical of freeze damage. But, as I also noted, I can only guess what it might be. I can tell you that most of the completely blocked lines I've dealt with over the years locally, have involved something placed in the lines -- golf balls being one example.

It is also possible to block lines with chemicals. Both stabilizer and borax will form SOLID plugs in line if added too rapidly. But you'd know if you'd adding some chemical at closing.

BTW, the last really cold winter we had here (Chattanooga area) *was* in the winter of 80/81. I remember rather well, because I still had a small plumbing repair business at the time, and I had to work my a## off for about 2 weeks, laying in icy puddles under houses and in holes, trying to get people's water back on. I could only work for my regular customers, there were so many calls, and had to tell others it would be at least a week before I could get to them. We had some local cold 'snaps' in the 80's, but 80/81 was the last sustained cold spell, with temperatures constantly below freezing, till this past winter.