Water heaters
How often should you flush a water heater?
For many tank water heaters, once a year is a useful starting point. The right interval depends on your model, water hardness, and the manufacturer's instructions.
Choose a schedule for your unit
Rheem advises most homeowners to flush a tank water heater about once a year. In hard-water areas, sediment can build up faster; its guidance suggests that every six months may be appropriate. Your product manual and warranty instructions are the best source for the actual unit. Save its model number so you can find the correct instructions later.
Tankless units are different: they may need a model-specific descaling process. Do not use a tank-draining tutorial as a substitute for tankless instructions. If you do not know the unit type or water conditions, ask a qualified plumber or the manufacturer before setting a recurring task.
Before anyone flushes it
Identify whether the heater is gas, electric, or a heat-pump model, and read the exact manual. Hot water can scald, and incorrect valve, power, or gas handling can cause damage. If the drain valve is stuck, the unit leaks, or you are unsure of the steps, schedule a qualified professional. Do not improvise around a gas or electrical problem.
Frequently asked questions
How often should I flush a tank water heater?
Annual flushing is a common starting point for tank water heaters. Check your model's manual and local water conditions; hard water may call for more frequent care.
Do tankless water heaters need the same flush?
No. Tankless systems commonly need model-specific descaling rather than the same tank-draining procedure. Follow the manufacturer's instructions.
Sources and scope
This is general planning guidance, not a procedure for servicing a specific heater.
- Rheem: How Often To Flush Your Water Heater — annual and hard-water timing.
- Tend: Water heater maintenance guide — records and visual checks.