There is no definitive answer to this question, as it depends on several factors, such as the type and size of your water heater, the hardness of your water, and how often you use hot water. Generally, it is recommended that you drain your water heater at least once per year. If you have a larger water heater or live in an area with hard water, you may need to drain it more frequently. Conversely, if you have a smaller water heater or live in an area with soft water, you may be able to get by with draining it less often. The best way to determine how often to drain your water heater is to talk to the experts at Hoffman Plumbing.