Water Heater Woes

Water Heater Woes 

Water heaters, they’re an RVer’s best friend, but boy-oh-boy can suddenly become a worst enemy! Here’s some tips to keep yours a best friend! 

Know What Yours Is 

There’s basically two types of RV water heaters: Tank type, and tankless. Which do you have?

This post only pertains to tank type, of which there are two main manufacturers, and they are very different, so that’s why you should know what yours is.

Suburban uses a steel tank, which requires a sacrificial anode rod as the drain plug to keep the tank from rusting.

Atwood/Dometic uses an aluminum tank, and since aluminum doesn’t rust, has a plastic drain plug which is specially made to melt if the water heater gets too hot, or shoot out if too much pressure just prior to the aluminum tank bursting (aluminum isn’t as strong as steel). That plug is a safety feature.

The Suburban Anode Rod 

If yours is a Suburban with a steel tank, you must use a magnesium anode rod.  Magnesium “rusts” or deteriorates instead of the steel tank walls.  Don’t go cheap on this and get an aluminum anode rod, which doesn’t “rust”.  I know some will say aluminum can be used, especially if the hot water smells, but that’s another issue, and aluminum is not the remedy.  You should drain your water tank a couple of times per year, and check that anode rod (remember it is the drain plug). If you see even a little bit of the steel rod that runs down the middle of the magnesium, replace it with a new one. Use Teflon tape on the last half or so of the threads to help seal it, but leave some of the first few threads showing so the tank makes steel-to-steel contact with the threads of the anode rod.  Does that make sense?  Most use a 1-1/16” socket.

 The Atwood/Dometic Plastic Plug 

 If yours is an Atwood/Dometic, the drain plug or drain cap is a special plastic and is a safety feature of the water tank. Replace yours if it looks brittle, cloudy, or if the threads are getting messed up. Please don’t fall for the salesperson’s “advice” telling you to use an anode rod, an electric heating element, or a drain petcock valve (sadly, they are sold at RV stores), which will put your RV and maybe even your family at risk. Most use a 15/16” (24mm) socket.

The Plastic (or lack of) check valves 

To put it briefly, cold water comes into the bottom of the back of the tank, heats in the middle and hot water exits out the top of the tank, there should be a check valve in the hot water outlet made of brass. It only allows water to flow out of the tank, not back into the tank.  Sadly, some manufacturers save some money by using plastic which will get brittle in a short period of time and leak! If yours is black or gray plastic, it should be replaced with good-quality brass check valves when the opportunity arises! Valterra makes a good brass check valve.

The Flush Out 

This is a very important maintenance step, it can be done every time you drain your tank.  A flush wand can be had at a very reasonable price of about $25, it attaches to a standard hose and provides a stronger more precise stream of water to break up and flush out the mineral build-up and material from the deteriorating anode rod that settles on the bottom of the tank. If that material builds up too much you can end up with cloudy water and impaired heating, among other things. It can also flush out any bacteria or mold that can grow in the tank causing the hot water to smell funny.

I hope you learned a few things here, and it helps you out there, on the road! I encourage you to always continue building on your RV knowledge, as knowledge is not only the cheapest but also the best way to further your enjoyment while you’re seeing the world on wheels! 

If I can help you do any of the above things, or show you how, please contact me!