If you want to learn more about what a water heater replacement service does, you might want to watch this video. Having maintenance done at least once a year can go a long way in extending the life of your water heater. This is also a good way to prevent future problems before you actually have to deal with them.
When maintenance is being done on your water heater, it is important to first look for leaks, and then check the air flow. Then, you will want to test the pressure and temperature relief valve, and then, check the rod to see how corroded it is. Finally, you will need to drain and flush the tank, in order to remove the sediment. In order to do all of this, you are going to need certain tools, including a garden hose, a bucket, needle-nose pliers, a screwdriver, a wire brush, Teflon tape, a multi-use cleaning brush, a 1-1/16 inch socket, 1/2 inch drive socket wrench, and a breaker bar. Before you start work, you are going to need to turn the gas supply off.
It would definitely be a good idea to watch this video if you want to learn more about things you need to do for water heater maintenance.