Step 6 · Prepare the New Valve
With the old valve removed, use a rag to clean the female threads on the water heater port, removing any old tape or sealant. Take your new T&P valve and wrap the male threads with 3 to 4 layers of Teflon tape. It is critical to wrap the tape in a clockwise direction (the same direction you will be turning the valve to tighten it). This ensures the tape tightens into the threads rather than unravelling. Carefully thread the new valve into the port by hand to avoid cross-threading. Hand-tighten it as much as you can.