How often should I flush my water heater?

Once a year for most tank heaters, and more often on hard or well water. Tankless heaters need a yearly descaling instead.

Updated October 26, 2026

Once a year is right for most tank water heaters. Flushing drains out the sediment that settles at the bottom, which helps the heater run efficiently and last longer.

Your setup	How often
Tank heater, town water	Once a year
Tank heater, well or hard water	Every six to twelve months
Tankless heater	Descale once a year

Male plumber in blue uniform inspecting white water heater with copper piping in basement utility room, draining sediment into bucket, white subway tile wall background, professional service photo. — A yearly flush during a maintenance visit.

Our water heater maintenance visit starts at $169 and includes a flush, a relief valve test, an anode rod check and a look at the venting. For step-by-step instructions to do it yourself, see our blog post "How to Make Your Water Heater Last Longer."