Step 8 · Tying into the Main Supply
This is the final plumbing step: connecting your new system to the water source. Ensure the main shutoff valve is still closed. Use a tubing cutter to make a clean cut on the main copper supply line after the shutoff valve. Clean and deburr the cut end of the copper pipe. Connect the main line to the hot and cold inlets of your PEX manifold. This is typically done using PEX-to-copper transition fittings. Push-to-connect fittings are a popular DIY option, or you can use PEX-to-copper sweat adapters if you are comfortable soldering. Repeat this process for the hot water outlet from your water heater, connecting it to the hot water inlet on the manifold.