Your washing machine’s drain hose should be 15 inches into the drain pipe, but not deeper as that can cause leaks. Most drain hoses come with a support bracket. That plastic bracket helps keep the drain hose from sinking too deeply into the drain pipe. If you want to connect multiple drains to one drain pipe – for example, a washer and dryer – you will need an extra y-piece for this. Your washing machine’s manual will also tell you more about the dimensions of the drain hose and the height of the drain pipe. These measurements can help you to correctly connect your drain hose to the drain pipe.