Step 3 · Measure and Purchase Replacement
Before disconnecting anything, use a tape measure to determine the length of the existing sillcock. Measure from the back of the exterior mounting flange to the center of the interior pipe connection. You must buy a new frost-free sillcock of the exact same length. Also, verify the connection type (in this case, a 1/2-inch or 3/4-inch female sweat connection) and the pipe size to ensure compatibility.