Standard recommendations for flushing home tank-type water heaters of all types are that they should be flushed monthly. Flushing means draining about one gallon from the bottom of the tank to eliminate accumulated sediment and minerals, which may coat the tank and inhibit the flow of water. All code approved tanks will have a drain valve at the bottom of the tank to make it simple.
Cautions:
1. Drain valves are often manufactured from plastic. Therefore, be careful when opening the valve with a wrench.
2. When opening a drain valve, beware that due to sediment that valve may not close to prevent dripping. Installing a hose cap after closing the valve will prevent dripping.
Flushing the tank should also prolong the life of the tank by eliminating substances that could eventually corrode the tank, causing it to leak and fail.
For more information, contact your local Extension office. See the eXtension web site to find Local Extension offices near you.