You may be familiar with the term “anode rod,” but do you really know what it is or what it does? If not, you are certainly in the right place. It’s a vital component of your RV water heater. If you have a bad RV water heater anode rod, you could be replacing your water heater much sooner than expected.
In this article, we’ll review everything you need to know about an RV water heater anode, from its function to installation.
Do I Need an RV Water Heater Anode Rod?
For starters, not all RV water heaters use an anode rod. The material of your tank determines this.
The two most common materials are steel and aluminum. Some manufacturers, like Suburban, use steel, and others, like Dometic, use aluminum. We won’t discuss the pros and cons of steel vs aluminum water heater tanks, but it is important to know which tanks require an anode rod and which do not.
Steel is vulnerable to rust when oxidation occurs; aluminum is not. Therefore, steel tanks require an anode rod, and aluminum tanks don’t. You don’t have to worry about an anode rod if you have a tankless or on-demand water heater. Even if you don’t need an anode rod, knowing what they are and how they work is still helpful. We’ll dig into that next.
Technician Tip: If you’re unsure what type of tank you have, it’s always best to contact the manufacturer for confirmation.
What Is an RV Water Heater Anode Rod?
An RV water heater anode rod is a long, cylindrically shaped piece of metal. The cap or plug contains threads that screw into the tank. The cap is then embedded with a long wire to which the metals are bonded. The bonded metals usually consist of magnesium, zinc, and aluminum.
The metals vary by manufacturer and region. For example, magnesium is typically suggested for soft water or high chlorine levels. At the same time, aluminum or aluminum/zinc are recommended for those with hard water or high sulfur levels.
It’s important to get the right one for your water type. If you use a magnesium anode rod instead of an aluminum or aluminum/zinc anode rod with hard water or water that contains high sulfur levels, you’ll likely start to notice a rotten egg smell when using hot water in your RV.
If in doubt, you can always get your water type tested, but the most common and popular choice is a magnesium anode for an RV hot water heater.
How Do RV Water Heater Anode Rods Work?
The anode rod is threaded into the tank and submerged. As city water is introduced, minerals come along with it. These minerals are potentially dangerous to your water heater’s tank, as they can oxidize and eat away or break down the metal. This sends metal flakes throughout your plumbing lines, potentially damaging seals, clogging faucets, weakening the tank, and increasing its potential to burst.
The anode rod is made of more reactive and corrosive metal than the tank. Therefore, the minerals will break down the anode rod before they break down the tank. So long as you have an anode rod, you don’t have to worry about tank rust and corrosion.
That said, RV water heater anode rods are sacrificial, meaning they are designed to be sacrificed and subsequently replaced. That is why it’s important to check them often. The water heater manufacturer usually outlines the RV hot water heater anode replacement guidelines.
Remember that as an anode breaks down, it will leave sediment at the bottom of your tank. This is why it’s important to flush and sanitize your tank often, one to two times a season, depending on use.
How Often Should An RV Water Heater Rod Be Replaced?
The time frame for RV water heater anode replacement depends on several factors, such as the amount of use, quality of water, and type of anode rod. However, they should be checked yearly and replaced if the size is less than 75% of the original unless otherwise specified. That said, with average use, they should last 3-5 years.
How To Tell If an RV Water Heater Anode Rod is Bad
The best way to determine if your anode rod is bad is to remove and inspect it. However, some other tell-tale signs would indicate this without removing.
- Rotten egg smell
- Cloudy and or discolored water
- Loud popping or cracking noises
If you notice any of these signs or symptoms, it might be time to check your RV water heater’s anode rod.
How To Select the Correct Size Replacement Anode Rod
When replacing an anode rod in the RV water heater, you must be sure you’re selecting the correct one. RV water heater anode rods are usually much smaller than those used in residential applications, so make sure you’re looking at RV anode rods only.
When picking out an RV water heater anode replacement, consider the size of the plug’s threads, the length, and the type of metal. The best way to find this information is to contact the water heater manufacturer, but you can also measure your old rod and the tank inlet to determine the proper size.
Technician Tip: Some RV water heater anode rods have a built-in drain which allows you to empty the tank without removing the anode rod. However, these models tend to drain very slowly, are more prone to sediment clogs, and can increase electrolysis in the tank.
Replacing the Anode Rod in an RV Water Heater
You’ll need these tools and materials to remove and install a replacement water heater anode rod:
- Appropriately Sized Socket
- 6” Extension
- Ratchet
- Breaker Bar
- Teflon/Plumber’s Tape
- RV Water Heater Anode Rod Replacement
- Water Heater Tank Rinser
Once you have all the supplies, you can get started. Although most anode rod replacements are fairly similar/standard, it’s always best to reference your owner’s manual beforehand.
Technician Tip: The RV water heater anode socket size is usually either ⅞”, 15/16”, or 1-1/16”.
How To Remove an RV Water Heater Anode Rod
While steps may differ based on the manufacturer, here are the basics for a successful RV hot water heater anode replacement:
- Turn off the power and shut off the gas supply. Most units have an easily accessible wall power switch, but you’ll also want to check your breaker panel. Then, turn off the propane supply at the cylinder(s).
- Disconnect city water, turn off the power to the water pump, and allow the water heater tank to cool for several hours. Then, run the hot water faucets with the water heater turned off until the water temperature has dropped to a safe level.
- Remove the exterior service panel and open the pressure relief valve on the tank by lifting the handle.
- Locate the water heater anode rod and use the appropriate socket and breaker bar to loosen the anode rod before removing it with a ratchet and extension.
- Inspect the anode rod for wear and replace it if it is outside of the manufacturer’s specifications.
- Clear sediment from the bottom of the tank before replacing the anode rod in your RV water heater.
Technician Tip: If water flow seems restricted when draining, use a rinsing wand or a dull plastic probe to remove any obstructions from the drain hole. Be careful not to scratch the tank’s inner lining. A sediment blockage at the drain opening can be removed with a metal probe, but a non-marring tool can be substituted to prevent the possibility of unintended damage from a hard or sharp edge. City water pressure can be used to rinse the tank so long as it is applied after the drain plug has been safely removed. It should not exceed 80 PSI to prevent the debris leaving the tank from traveling at dangerous speeds, risking injury or damage. The city water pressure method is more difficult to control and may be less effective than a curved wand.
How To Install an RV Water Heater Anode Rod
To install a new anode rod and start testing your water heater, follow these steps:
- Clean the drain plug’s thread insert with a brush.
- Wrap anode rod threads with plumber’s or Teflon tape.
- Hand-tighten the anode rod into the tank, being sure not to cross-thread.
- Tighten the anode rod to the manufacturer’s specifications.
- Close the pressure relief valve.
- Turn the city water and or water pump back on and check for leaks.
- If no leaks are present, open the gas valve and resupply electrical power.
Schedule an RV Hot Water Heater Anode Replacement
The impact of not having a functioning anode rod can be significant, which is why it’s important to check yours regularly. If you don’t, you could be left with an expensive repair bill. Hopefully, this article gave you a better understanding of what anode rods are and how they work so you feel more confident checking them yourself.
If you prefer not to do this yourself, your Certified CW Technician can inspect your anode rod at no additional cost when purchasing a Water Heater Service Package.
Take a look at some of these other RV water heater articles below:
- Why Isn’t My RV Hot Water Heater Not Working?
- How To Winterize an RV Tankless Water Heater
- What to Look For In an RV On Demand Water Heater
Let us know in the comments below how often you check and replace your water heater anode rod.
The information provided in this blog is for general informational purposes only and not intended to take the place of professional service providers. While we strive to provide accurate and up-to-date information, we make no representations or warranties of any kind, about the completeness, accuracy, reliability, suitability, or availability with respect to the information, products, services, or advice contained on the blog for any purpose. Any reliance you place on such information is therefore strictly at your own risk. In no event will we be liable for any loss or damage including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from loss of data or profits arising out of, or in connection with, the use of this blog.
