How Often Should Water Heaters be Drained?

As a multi-family property owner or manager, maintaining the water heaters across your properties isn’t just a matter of efficiency—it’s essential for tenant satisfaction, regulatory compliance, and cost control.

One key maintenance task that is often overlooked is draining or flushing water heaters. This simple yet critical procedure can significantly extend the life of your water heaters and reduce the risk of unexpected failures.

Why Draining Matters

Water heaters gradually accumulate sediment and mineral deposits over time. These deposits typically settle at the bottom of the tank in standard water heaters. The result? Decreased energy efficiency, longer recovery times, higher utility costs, and an increased risk of system failure.

Draining and flushing the unit helps remove these deposits, which restores the unit’s performance and efficiency. For properties with multiple units, this adds up to noticeable savings and fewer emergency maintenance calls.

Standard Tank Water Heaters: Once a Year—At Least

For standard tank-style water heaters, most manufacturers recommend flushing the tank once a year under normal water conditions. This helps remove sediment that can insulate the burner from the water, forcing the system to work harder and wear out faster. In multi-family settings where hot water demand is high, annual flushing is a smart preventive measure that can help avoid mid-winter breakdowns and service interruptions.

Hard Water Areas: Every Six Months

If your property is located in a region with hard water—a common issue in many parts of the U.S.—you may need to flush the water heaters twice a year. Hard water contains higher levels of calcium and magnesium, which accelerate scale buildup inside the tank. More frequent maintenance can help mitigate the effects of this mineral-rich water, especially in high-demand buildings where water heaters are constantly cycling.

Tankless Units: Don’t Forget Descaling

Tankless water heaters also need regular attention. While they don’t have a storage tank, mineral buildup can clog the heat exchanger and reduce efficiency or cause the unit to overheat. Most manufacturers recommend flushing and descaling a tankless water heater at least once a year—or more frequently in hard water environments. This usually requires a pump, a descaling solution, and the proper setup, so it’s best handled by a licensed plumber.

The Bottom Line: Regular Maintenance Pays Off

Draining and flushing water heaters should be part of your routine property maintenance schedule.

Regular attention ensures optimal performance, extends the lifespan of each unit, and reduces the likelihood of costly emergency repairs. Most importantly, it helps you deliver reliable hot water service to your tenants—something they notice and appreciate.

Check the manufacturer’s maintenance guidelines for each unit type and consider setting calendar reminders or partnering with a plumbing service provider for scheduled maintenance. A little preventive care today can save a lot of time, money, and headaches tomorrow.