How to Clean an RV Water Heater Tank: Step-by-Step Guide

Keeping things clean and well-maintenanced is an important part of RV life.

Things like proper waste removal and keeping your freshwater tank clean are vital. But one of the most often overlooked is cleaning your water heater tank.

To heat up water in your RV, the water in your freshwater tank needs to pass into your water heater tank before being heated up. 

That means it needs regular cleaning just like your freshwater tank.

Below, we’ll show you exactly how to do it as well as explain how RV water heaters work, how often you should clean yours, and more.

First, let’s talk about how they work to understand more about why they need to get cleaned regularly.

How Do RV Water Heaters Work?

An RV water heater uses energy to heat up water within its tank, which it funnels from your freshwater tank.

The type of energy used to heat can be one or a combination of:

• Electricity (generally the fastest and most convenient)
• Propane (ideal for boondocking)
• Or engine heat (most energy efficient)

Some water heaters use a combination of the above (typically electricity + one of the others) to get the benefits of two energy sources for either added convenience or energy efficiency.

How to Clean an RV Water Heater

Now, let’s talk about how to clean an RV water heater tank. 

Your water heater should be cleaned in much the same way as your freshwater tank, so if you’ve ever done that before you’ll find some of these steps to be similar.

1. Turn off your water heater + water source

Before conducting maintenance, your water heater needs to be turned off. You’ll also need to shut off your water source if you’re currently connected to shore water or another source. 

To turn off your water heater, you can do it via your main control panel or there should be a switch on the heater itself. 

2. Release the pressure valve

Next, you’ll need to release the water pressure valve on your water heater, which is typically located somewhere near the top and controlled by a small switch. 

3. Open the drain

You’ll likely need a socket wrench or similar tool, depending on your water heater and whether you have an anode installed already. This is typically located near the bottom of the water heater. 

Keep in mind that if there is any water in your tank when you open it, it will come rushing out as soon as it’s opened. The water may be quite hot, so be prepared and take precautions. 

4. Flush your tank

Next, you’ll use an RV water heater flush wand (like this Camco model) to flush the tank:

Simply take your wand, connect it to a water hose, and turn the water on. The wand will have a pressure valve so you can turn the water on via the hose without letting the water come out of the wand until you want it to. 

Next, place the wand into the tank and turn the wand valve. Move the wand around to make sure you get all of the walls, floor, and roof of the tank as well as the corners. 

Do this for about ten minutes for a nice long, thorough cleaning. 

Cleaning your tank with a flush wand allows you to remove any sediment that has built up over time, which is a big part of keeping your tank not only clean but smelling good (or rather, not smelling). 

5. Inspect your anode rod

Now that you’ve opened your tank, take this time to inspect your anode rod if you have one. They’re a vital part of keeping your water heater in good condition, so you’ll want to replace them about every 3-4 years. 

You’ll notice it get worn down over time, starting as a solid rod and over time turning into a thin point with build up. 

Replacing an anode is pretty simple and straightforward. If you need more information follow the instructions in this video:

6. Reseal the drain and turn your water back on

Close the drain and turn your water source back on (don’t touch the pressure valve yet and keep your water heater turned off). 

Once that’s done, make sure to wait about 10 minutes to be safe as the tank refills. 

As soon as you see water come out of the top of the water heater, reclose the pressure valve. If you close the valve sooner than that, it won’t be properly pressurized, so make sure not to do it until the tank is full. 

7. Turn your water heater back on and inspect

Next, you can turn your water heater back on and check to make sure everything is working correctly.

Make sure there are no visible leaks, that your water is heating properly, and nothing else is out of place.

How Often Should You Clean an RV Water Heater?

Your RV water heater should be cleaned a few times per year, ideally twice if you’re only using it over the Summer (beginning and end) or up to four times if you use your RV full-time.

An easy way to keep track of this is to clean it at the beginning or end of each season, but when you do it is less important than how often. 

If you wait too long to clean your water heater, sediment will build up which not only leads to unclean water but a bad (often egg-like) smell. 

Should I Drain My RV Water Heater After Every Use?

If you RV full-time, stick to cleaning your water heater on a schedule, about every 3 months.

However, if you only use it for the occasional trip over the Summer (or any other time), make it a habit of cleaning out your tank at the end of each trip if it will be a while before you use your RV again. 

This will ensure your water heater stays clean and nothing is allowed to build up over time between uses.

Things That Can Go Wrong with RV Water Heaters (and How to Avoid Them)

Now, let’s quickly cover a few things to look out for that can go wrong with your RV water heater. 

The two main problems that can arise with RV water heaters are:

• Corrosion, and
• Rust

Both can build up over time due to a combination of various elements (such as steel) coming into contact with moisture. 

Fortunately, you can use an anode rod to solve these common problems. 

An anode rod is a solid piece of aluminum or magnesium, about the length of a cooking spoon, that screws into a dedicated opening in your water heater compartment.

It releases electrolytes into the water that prevent corrosion, in a way absorbing that potential damage over time so that the tank remains in good condition. 

They don’t last forever, though. You’ll want to make sure to keep an eye on your anode rod and check it occasionally as they last about 3-4 years depending on the quality of the water you’re using. 

What is the main benefit of an anode rod? Sure, they prevent corrosion, but can’t you just replace your water heater tank?

Rods typically set you back about $20, while water heater tanks are closer to $800-1,000. Big difference. 

By using an anode rod, you’re able to save your water heater from damage and prevent costly repairs.

Keep Your Water Heater Clean Year-Round

Keeping your RV water heater clean and in good condition doesn’t take much work, but it’s an essential part of RV maintenance and staying healthy on the road. 

Over time, buildup can cause erosion and rust which will eventually ruin your tank. 

It’s a costly repair, so make sure to maintain it properly with an anode rod and regular cleanings to not only keep your water clean but your tank in good working order.