Step 6 · Restore Water and Check for Leaks
Ensure the water heater's drain valve is fully closed and disconnect your garden hose. Go to the cold water inlet valve and turn it on SLOWLY. This prevents a 'water hammer' effect that could damage your pipes. You will hear water filling the tank. Let the hot water faucet that you opened earlier continue to run; you will hear it sputter as air is pushed out of the lines. Once water flows from the faucet in a steady, air-free stream, you can turn it off. Now, meticulously inspect the new connection where the expansion tank is installed. Use a dry paper towel to wipe around the joint; it will make even the smallest bead of moisture obvious. If you find any leaks, you must shut off the water, drain the system again, and re-seal the connection.