Over time, water heaters collect the bits of solid sediment in tap water. Some of the sediment passes through the heater and runs through pipes, but a good portion of it collects at the bottom of the water tank. This can decrease the amount of hot water your tank can hold due to the lost space. You can drain the tank to manually remove the sediment and keep the tank running as it should. A garden hose is a useful tool that can be connected directly to the hot water heater to drain the water and sediment inside.
Flip the breaker in your electrical breaker box that corresponds with your water heater, if it is electric. If it is a gas water heater, turn the red control knob to the "off" position.
Turn the cold water knob at the top of the hot water heater to tighten it all the way. This will stop water from running into the tank.
Pull upward on the pressure release valve at the top of the tank. This will allow the water in the tank to be drained out.
Screw the female end of a garden hose onto the threaded tap at the base of the tank. The female end is the end with the threads inside, rather than outside.
Run your hose outside or into a utility sink for draining.
Grasp the connected end of the garden hose and turn the valve, between it and the tank, counter-clockwise until you feel a rush of water draining into the hose.