RV Water Heater Problems, Solutions and Maintenance

                                            By Warren Petkovsek

     Well, here we go again. ‘Another little article that will, hopefully, be of help to my fellow RVers. I’ve had folks ask me, “Where do you get all of the ideas for your articles?” The answer is that, with the exception of wrecks and fires, I’ve made just about all of the mistakes that an RVer can make and I feel compelled to write about them in order to save someone else a little grief. Like my dad used to say, “Do as I say, not as I do.” Well, my latest little RV inconvenience was a problem with the water heater that could have possibly ended our trip and it certainly was inconvenient. Hey – nobody likes cold showers so let me explain what happened and how to avoid it so that this never happens to you. Here we go.
     On an RV trip from our home on southeast Texas to Beaufort, South Carolina where our son and his family live we noticed a drop in water pressure when hot water was needed. Hot water was barely a trickle and sometimes we actually got no hot water at all. For the rest of the trip it was either the park’s shower house or cold showers for us and we had to use a tea kettle to get hot water to wash dishes. OK. Why did we lose hot water pressure when cold water pressure was fine? We couldn’t figure it out at first. Well, as usual, we talked to other RVers in the park and they all graciously offered us any ideas or suggestions that they had. One item kept coming up in these conversations was the water heater anode rod. Well, you may or may not know that these RV water heaters have this anode rod or why it is needed. I knew about it and I even knew that people changed them out from time to time. Like most of us I subscribed to the “If it ain’t broke, don’t fix it” philosophy and never even thought about it. Heck – we used our first trailer for thirteen years and never gave the anode rod a thought. We hope the folks that bought the rig haven’t had any problems. (Note: Hey Gilbert! I hope you are reading this.) Let’s start out by explaining what this anode rod is and how it works.
     Anodes are sacrificial in nature. All metals (like the tank in your water heater) will eventually corrode when exposed to water. The anode rod will sacrifice itself and corrosion will attack it before it attacks the tank of your water heater. Residential water heaters do not generally have anode rods because the tanks in these are either made of fiberglass or are coated with something that will retard or prevent corrosion. Since the anode rod gets all this corrosion it stands to reason that it will corrode before your tank. This is a good thing, but if you ignore water heater maintenance three things could potentially happen; all of them are bad. First, the anode rod will completely corrode and stop protecting your tank. It could even possibly fall apart like mine. Second, your water heater tank will corrode and possibly fail. Third, pieces of the failed anode rod or loose chunks of calcium or other mineral deposits from the various camp ground water supplies could possibly travel down the water line plugging up your plumbing. This is what happened to us on our trip. A chunk of something solid got stuck in the small check (non-return) valve at the outlet of the water heater. Also a fairly small chunk got by the check valve and found its way to our kitchen faucet. Now we couldn’t even wash dishes. ‘Time for a Wal Mart run to stock up of paper plates! The faucet couldn’t be unplugged and eventually had to be replaced. Well, after nearly three decades of RVing I finally became a believer of water heater maintenance. It’s not hard at all. Let’s go over the procedure for this simple job. Here we go.
     The first step is safety related so it’s very important. Turn off the water heater (both LP gas and electricity) and run hot water for about ten minutes so that the hot water in the tank will be replaced by cold water and you won’t get burned when you drain the tank. The remainder of the job is done outside the rig. The next step is to turn off the water supply to the RV and briefly open a hot water faucet in order to bleed off any remaining pressure. Next you will open the service panel door on the outside of the rig where the water heater is located. Now you will need to vent the tank in order to facilitate draining. You do this by opening the vent lever on the safety relief valve. It’s not hard to locate this valve. When you find it just pull up on the small metal handle. Be sure to stand to the side so that you don’t get wet in case there is still some water pressure. Now that the water is turned off and the tank is vented it’s time to drain the tank. You will find a large plug down in the lower part of this compartment. This is what you will remove in order to drain the tank. The anode rod (or what’s left of it) is also attached to this plug. To remove the old plug and anode rod you will need a six sided 1 & 1/16 inch socket wrench, possibly with an extension and the appropriate ratchet or breaker bar. It would probably help to spray the plug with a little penetrating oil or WD-40 to loosen the threads. You probably should do this the day before you do the job. OK now you just use your wrench to remove the old anode rod. This will drain the tank so stand clear if you want to stay dry. Now that you have the old anode rod in your hand you might want to check its condition out of curiosity. My old rod fully explained my water pressure problem. There wasn’t very much of it left (see picture). While the tank is draining you might want to watch and see if any chunks are coming out with the water. I had a lot of that. ‘Probably a couple of big double hand fulls (see other picture). OK, by now you’ve probably noticed that the drain hole is not exactly on the low point at the bottom of the tank and all of the water and solids cannot completely drain. The drain is on the side of the tank in order to make it accessible for service. You still have to worry about how to get all of those little solid chunks out of the bottom of your tank (and away from the rest of your plumbing). In one of the pictures you can see that I used an old piece of garden hose attached to my water hose so that I could slip the end into the tank and flush out solids. I had to repeat this procedure several times until I was satisfied that the tank was free of debris. There is also a tool that you can use instead of an old piece of garden hose for flushing your tank. It’s called “Tank Saver” and is available at Camping World and also at most RV dealers. It attaches to your water hose, has a shut-off valve and narrows down to a small diameter for a good high pressure flush. The tip is slightly curved so that you can easily wash the walls of your tank and also push the solids toward the drain hole. I didn’t have it when I serviced my water heater, but I picked one up to use for future jobs.
     Now that you have drained your tank and it is flushed free of solids it’s time to put your hot water system back in service. Take your new anode rod out of its package and wrap the threads with Teflon tape in order to prevent leaks and stuck threads. Just a couple of wraps will do. Insert the new rod into the tank drain and tighten the plug being careful not to cross-thread the plug. Now you can turn on the water to the RV and begin filling the water heater. While you are doing this you can leave the vent on the safety relief valve open in order to facilitate filling the tank and prevent air bubbles in the system. Be sure to stand clear of the vent unless you want an unexpected shower. When water appears at the vent you can close the vent on the safety relief valve and turn the water heater back on. You may still get a little sputtering at your faucets due to trapped air bubbles, but this will soon pass.
     OK, that should have been fairly painless (both the job and reading the article). I for one will never neglect my water heater again. The job of servicing this appliance is just too easy and painless to neglect. As for me, I will drain the tank and inspect the anode rod every six months. I also keep a new rod on hand just in case the old one looks bad.
Well, that’s all for now. A few days ago I couldn’t even spell plumber and now I am one. That means that you can easily do this job too. Trust me – you don’t want to lose your hot water by neglecting a job that is this easy.

Happy trails!

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Warren Petkovsek has been an avid RVer for over several decades. He lives in Lumberton, Texas with his wife, Myra. A former teacher, band director and professional musician, Warren is now retired from the petrochemical industry. In addition to being a freelance writer he is also a school volunteer, a Texas State Park volunteer and has been a Boy Scout Leader for many years.
Warren would be delighted to answer any RV related questions that you may have and would be delighted to send you some or all of his other articles. He can be contacted at
wpetko@sbcglobal.net .