If you choose to drain the water heater, and you have a Suburban, it takes a 1 1/16th inch socket to fit that plug. Release the pressure on the system by opening a faucet. The 1st time removing the drain plug and attached anode rod, it might be hard to do.....they screw that puppy on like it should never be removed.
Beware, you will probably get wet !!
Many people (myself included) only empty the water heater once a year when we winterize.
Chap , DW Joy, and Fur Baby Sango
2006 Ford F150 Super Cab 4x4
2008 Surveyor 263