The Tank › replaced water heater, still leaking from pipe outside › Reply To: replaced water heater, still leaking from pipe outside
If it’s thermal expansion — and it probably is — you can easily test for it. Using the link on the left side of the Tank topics index, go to Tanklets and click on Temperature/Pressure Relief Valves.
There are really only two possibilities: bad T&P or thermal expansion. It’s unlikely it’s the first since you replaced that several times and have a new heater. It’s unfortunate that somebody got you to buy a new tank to solve such a simple issue.