If you are replacing the old water heater with a new unit that is similar to the old one, you will not find it very difficult to replace it. Moreover, if you follow the steps below, it will certainly make your task much easier.

- Shut off the water supply

- If you have a gas heater, shut off the gas supply, or if you have an electric heater, turn off the power supply.

- The next step is to drain the water from the tank. If you do not have a floor drain underneath the valve, you can connect a hose to the drain valve, near the base of the tank. Run it to a nearby drain or outdoors, and then open the valve.

- Unscrew the inlet and outlet fittings from the top of the tank, using two wrenches.

- If you have a gas water heater, turn off the gas inlet valve. Disconnect the union or flare fitting between the gas supply pipe and the inlet valve. You can use two wrenches to disconnect the same. You will also find a flue hat at the top of the tank. It expels gases into the flue. Remove this flue hat as well.

- Remove the old water heater.

- Set the new water heater carefully in place so that the burner and controls are accessible. Make sure that there is at least six inches of clearance around its perimeter, and it is away from any flammable materials.

- It is better if you fill the base with pieces of asphalt shingles or plastic wedges.

- Wrap the threads of the heat trap fittings with pipe-wrap tape.

- Connect blue thread of the fittings into the cold water inlet of the water heater, and red into the hot water outlet.

- Be careful while connecting the same. Make sure that the arrows are marked on the fittings point in the water flow direction.

- On the inlet and outlet pipes of water heater install the new flexible connectors.

- Make sure that all connections are complete.

- Open the shutoff wall and fill the tank.

- Open a few hot-water faucets so that the air in the pipes should bleed off.

- Now assemble the gas pipes per the manufacturer's instruction.

- Brush soapy water on all the connections, and carefully watch it should not produce any bubbles. If it does, recheck the connection once again.

Some Other Handy Tips

- Check with your local building department and confirm whether your home is in an earthquake zone. Install straps around the new water heater.

- If the height of the new tank is different from the old one, you will have to use flexible pipe connectors for the water inlet and outlet. This will make them able to bend whenever it is needed to make the hookup.

In case the pipes are not threaded, replace them with threaded nipples. Use an adjustable wrench to adjust the connectors to the nipples.

Hence, if you follow the above steps and the tips, you will find it very simple to replace a water heater.