That sounds like quite a bit of repairing for the first 2 years, but sometimes things like this happen so I wouldn't say it's indicative of the brand without a larger sample size. Overheating pumps can act just as you described and I doubt the retailer would have taken the time to install a new pump under warranty if it wasn't the issue as they saw it. However, if it was a common problem for that year I would probably want to know whether my pump was replaced with the same model with potentially the same problems, the same model but they worked out the kinks, or a different model that doesn't have those issues.