Some RV water heaters are made of aluminum and do not require a sacrificial anode rod. Our water heater is not that type.

If you read the periodic maintenance activities, you would know that we plan to check the water heater anode rod about every three months. They are normally expected to last around five years, so every three months seems excessive. If your water has a lot of softening (i.e., sodium from salt), the anode rod can degrade in as little as six months. A salt based water softener removes minerals, but it adds a small amount of salt to the water. As the ocean shows, salt makes water more corrosive to metal.

The anode rod above is not 100% used up. At 100% used up, it would be the thickness of the wire for the entire length. It looks to be about 50% – 60% used up, so it would probably last another 2 – 3 years. Our concern is that sometimes the anode breaks off when the wire is exposed at the base, just like the picture of our anode above. If they break off at the wire, the rod bounces around in the tank while you are driving, and this damages the coating inside of the water tank. These suburban anode rods are only about $16 each on amazon, so it is not expensive enough to risk the water heater. They might be cheaper elsewhere, but make sure to buy the correct style and length for your water heater. They come in at least 1/2″ and 3/4″ sizes.

On the note of anodes and water heaters, I never realized that home water heaters have anode rods. From the sound of it, they are partly used to control the lifespan of your water heater. When you buy a water heater with a six year guarantee, it has a shorter anode rod than the water heater with a ten year guarantee. If you buy a six year water heater and replace the anode rod every five years, you can get your home water heater to last much longer than six years. I read that it can be a bit of a task. I am guessing that you need shut off the intake valve, drain some water to remove the pressure, and then change out the anode rod. I assume there is some risk of scalding, if you are not careful. I think the anode rods are cheaper than a water heater, but not cheap. You also have to remove the original anode rod shortly after the water heater is installed, put anti-seize on the anode rod threads, and screw it back in. This increases the chance that the anode rod can be actually removed in five years to replace it.