I have been in the process of repairing things in my used 2007 pup before the maiden voyage. I get to the water heater and have no idea what to do or how to use it. I read as much as I can without asking noob questions here. Research told me to ensure tank is full before lighting. I figured out how to get the tank full by turning on hw faucet and running till air stops. Next I try to light pilot, no luck after long time trying, back to the boards for info. During my research I found some info on anodes, didn't know about that. looking at my heater anode nut, it is rusty and I figured it may need to be changed out. I try the PRV a few times but seems to not purge anything and kinda sticking. It wont pull out too far but seems to go back in place. On to the anode. I found an impact and 1-1/4 socket then went to work. It was rusty and on tight not moving much. All of a sudden it spun off like a nascar lug nut and pressurized sludge blew out . My rig is 36" off the ground and my face was directly in front of the blast. I did not have safety glasses on at the time. Grit and slime got in my eyes and I was covered in crap. I had to make my way out of the shop and through the building half blind to get to a water station to wash out my eyes, thank god it wasn't hot water. Lesson here is, be Shure you have cold beer on hand for unexpected mishaps. No telling how long it had been since the tank was used or maintenance last. It appears the anode has never been changed, all the corroded magnesium is in the bottom of the tank, my hair and on the shop floor. The anode was gone, all that was left was the nut and a rod that the magnesium is applied to. pic. I will be replacing the stuck PRV also, BTW removing the PRV with a basin wrench is works good. So any new used pup owners be sure to check, service and maintain your water heater. Lastly safety first.