Why is my water heater relief valve dripping?
What the sources say
Kentucky code says temperature and pressure relief valves must be installed according to manufacturer requirements. Rheem manuals warn not to plug the relief valve outlet. Bradford White manuals warn not to thread, plug, or cap the discharge line and not to place a valve between the relief valve and the tank.
Dripping may point to thermal expansion, high pressure, overheating, valve failure, discharge piping problems, or a water heater that needs replacement. The source-backed answer is simple: keep the relief path open and get the system checked.
Central Kentucky note
In Lexington and Richmond homes, this often shows up after a water-heater change, pressure change, or old valve wear. A licensed plumber can verify pressure, temperature, expansion control, valve condition, and discharge piping.