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.
[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.