When it comes to installing a gas heater plumbing system, there are certain valves that you should use to ensure the safety and efficiency of your system. Most temperature and pressure relief valves (T&P) are factory-installed. If your relief valve T&P is in a different box, it must be installed in the opening marked as relief valve T&P.
Using the new T&P relief valve
supplied with the new water heater is essential and should not be reused. Flexible gas line is also recommended, as it can withstand movement and is generally required in earthquake-prone areas.To begin the installation process, you must first remove the threaded “T” shaped leg and the drip leg and then remove the gas control valve nozzle from the water heater. After making the gas connections, it is important to use a soft-bristled brush to apply a mixture of water and dish soap or soap bubbles for children to all gas pipe connections and to the flexible gas connector (if used). For homes with copper pipes, consider purchasing a gas water heater installation kit (available at hardware stores and home centers) with compression fittings that don't require soldering. Because the water heater is new and the tank is cold, some condensation (drops of water) may build up on the floor the first time the water heater operates. The installation kit includes a flexible gas connector with compression fittings for connecting the house's gas line to the gas control valve of the water heater.
Even if you have experience working with gas pipes and pipes in the past, it is always best to contact your local inspection department for safety reasons.