Replace the old flexible gas connector, if there is one. Gas connectors are flexible corrugated pipes that are usually silver, brass, or yellow colored. They are usually about twelve to eighteen inches long. Gas connector manufacturers do not recommend reusing old gas connectors. Replace the cold water shutoff valve, particularly if it is an old gate valve. Gate valves usually have a wheel type handle and look like garden hose valves. Gate valves may seize open and will not close or they may leak with age. It is less expensive to replace an inexpensive gate valve with a better quality ball valve while the plumber is there to install the new equipment.