What do the numbers on a tire mean? The DOT number appears on the sidewall of all tires intended for sales in the U.S., and designates the location of manufacture, the week and year of production, and the specific tire.
Water heater anode rod or sacrificial anode is the important component part with only one purpose; to protect metal tank from corrosion. Use this article to learn how to replace the anode, installation tips, how it works, about different types and when to use each one.
You're spot on about draining your water heater. Very good Ible. Many years ago I had to replace my water heater. Where I bought the heater the technician told me besides draining the heater, replace the anode rod in the heater every 2 years, and in most cases you'll better than double the life of your heater. He told me he has the same water heater in his house for 23 years. I've been changing mine every 2 years.