Step 2 · Shut Off Water and Drain System

Locate the main water shutoff valve for the house and turn it completely off. Open the lowest faucet in the house (like a basement or outdoor spigot) and the highest faucet to drain all remaining water from the supply lines. This prevents water from spilling when you cut into the existing pipes. If you are tying into an existing drain stack, ensure no water is being run from fixtures above.