[header] How to drain a water heater [title] Turn off your water heater. [step] You do not want to drain a water heater that is in operation. [substeps] If you have a gas-powered water heater, turn the switch to " pilot " to keep the water heater's pilot light on, but stop the water from heating. 
If you have an electric water heater, switch off the electrical switch that connects the heater to the electricity. This may be a switch in a board above the heater.