Before removing the old gas valve from the water heater, users must first turn off the gas and the cold water supply. They can then remove the old valve using pliers or a screwdriver, depending on the model of water heater. A pipe wrench is necessary to remove the valve.
The first step in replacing the gas control valve of a water heater is to turn off the gas supply to the water heater and then turn off the gas control valve itself. Be wary of gas leaks, as this may be a dangerous situation and can require professional to fix it. Next, the cold water supply to the water tank must be turned off and the tank drained if possible. Use a bucket to remove as much water as possible and then remove the discharge pipe.
At this point, use a pipe wrench to remove the old gas control valve from the system. Some models may require a screwdriver or pliers to remove it. The new valve is then attached to the system using the pipe wrench, and tightened so that there are no leaks. The discharge pipe may now be reattached to the water tank and the water supply turned back on. Finally, turn on the gas supply and control valve, check the gas pressure and check for leaks.