RV Tip: Water Heater Maintenance

If your RV water heater is like ours it gets a lot of use. It’s recommend that RV owners maintain their water heaters once a year, especially in areas where the water has a high mineral content. Unfortunately, many neglect this basic yet very important part of RV ownership and eventually suffer the consequences in poor operation and high maintenance costs. Fortunately, maintaining your RV’s water heater isn’t very difficult, but it does take a little forethought and planning.

Water heater maintenance consists largely of draining and flushing out the tank. You may be wondering why doing this annually is necessary. The reason is because of mineral build-up. Over time, the minerals contained your your water builds up and forms a corrosive coating over the internal components of your water heater. These internal components include the tank itself as well as the heating element and heating tubes. You may think that mineral build-up isn’t that big of a deal, but you might be surprised by what you see the first time you perform this maintenance. Each time I’ve drained my water heater in the previous RV’s I’ve owned, I’ve been shocked at the amount of mineral build-up. Without a doubt at least a 1/2 cup of minerals has come out each time I’ve performed this maintenance. Here are the basic steps needed to maintain your water heater:

1. Drain Tank: This is a pretty simple process but can get you hurt if you’re not careful. First, make sure the water has cooled off sufficiently before you begin work (many like to turn off their water heaters the night before). Don’t take this lightly. Newbies often get burned from the scalding hot water, so please don’t overlook this step. Next, release the pressure in your tank by opening the pressure relief valve at the top of the tank. With the valve open, remove the drain plug from the bottom of the tank to allow the water inside to drain out. For Suburban models, you’ll need a 1 1/16 inch socket to remove the anode rod while for Atwood models, you’ll need a 7/8 inch socket to remove the drain plug (Atwood models are made of aluminum and don’t require an anode rod).

2. Flush Tank: To perform this task you’ll need a so-called flushing wand. You can purchase one at any RV Parts store for around $7 and is a good item to have in your RV maintenance kit. These connect to a standard garden hose and come with a small valve to turn the water on and off. Simply, insert the wand into the drain hole and turn on the water. Make sure you rotate the wand as you flush out the tank to ensure all areas of the tank are getting clean. At first, the water draining out will have a milky appearance from the high mineral content, but will soon clear up. When the water clears up you know that the tank is clean.

View showing white mineral deposits around the drain hole.

3. Clean Tank: This process is a bit more involved and should be done every two or three years (the periodicity depends on the quality of the water where you live). This is done by using a combination of white vinegar and fresh water, usually a 50/50 ratio. Getting this mixture into your water heater tank can be accomplished in one of two ways: by using your RV’s winterizing system intake or by attaching a hose with the appropriate sized fitting directly to the water heater drain and filling the tank manually. Once the mixture is in your tank, turn on the water heater and allow the hot water inside to boil for at least a couple hours, more time is better. Once this is accomplished, turn off the water heater again and allow the water inside to cool off. Remove the drain plug and flush out the tank again using the flushing wand procedure as stated above.

View showing what little of my anode rod remained.

4. Inspect Anode Rod (Suburban water heaters only): This inspection is simple yet very important. The rod portion, which is made of magnesium, is actually molded to the drain plug and acts as a magnet of sorts to attract the corrosive elements and minerals found in your water. The anode rod is essentially sacrificing itself for the good of your water heater. Anyhow, the anode rod is quite large when brand new and installed. Over time, the rod deteriorates and should be changed out as required. This is another reason why it’s important to clean and inspect your water heater annually. It’s also a good idea to have a spare anode rod on-hand at all times. Camping World sells these for around $20 a piece.

So how long does an anode rod typically last? It depends. The mineral content where you live really plays a large role in how often you need to change yours out. Here in Arizona I can usually go two years before I need to replace mine. But I know many who live in areas where the mineral content is low, like in Washington State, Idaho, and Montana, can go as long as four years and sometimes longer.