- Feb 2, 2022
- 4 min read

Changing The Sacrificial Anode Rod In Your Caravan

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How to change a caravan hot water system Anode Rod

One of those vital caravan jobs to keep up with is changing the anode rod in the hot watr system tank. The anode is a sacrificial rod made of magnesium, which attracts the corrosive components in water, protecting your hot water system tank from corrosion. I personally had never heard of this until we purchased a caravan and the anode rod needed replacing right away.

Keeping regular with this job will prolong the life of the hot water system tank as the anode rod takes the corrosion on itself. Once the anode is fully corroded, it is no longer able to do what it was designed for and it will leave the hot water system tank to bear the corrosion from this point on. This will then leave you needing to replace the system, an expensive exercise which can be avoided in a few quick steps.

What causes an anode rod to corrode so quickly?

There are a few different reasons why your rod may corrode faster.

It can depend on how much water is travelling through your hot water tank. The more water travelling through brings more of the corrosive elements to pass through.

The water quality can be a deciding factor as to how quickly the rod will corrode. If your water has added water softener, ie sodium, this will cause the rod to corrode quicker too.

The type of material the rod is made from is also a factor. The magnesium rods will corrode a little quicker than the aluminium rods.

You won’t need many tools to do this, nor a lot of knowledge either. When you’ve done it once, you’ll be able to do it for yourself each time it needs to be done, saving you money on labour if you were to take it to a caravan service centre. It is recommended to check the anode at least every 6 months. Once the anode is between 50% - 75% corroded, that is a good time to replace with a new rod.

It’s important you complete this job when the water in the tank is cool. Once you crack the nut of the anode rod, water will more than likely start to leak out. And depending on the pressure it’s under, it could come out at a fairly quick rate. To prevent burns, ensure the water is cool.

Tools you will need:

- ¾ or ½ inch Drive Ratchet

- Extension Bar

- 27mm Socket

- Plumbers Tape

- Anode Rod

How do we check / replace the anode?

1. Start by turning off the water pump and also the gas and electrical power to the water heater and if you are connected to mains water, ensure this is turned off also.

2. Allow long enough for the water in the tank to cool, to prevent burns.

3. Go inside the caravan and turn on the tap to release any pressure from the water tank.

4. Place a bucket underneath the door to the hot water system, as water will start to leak out when you release the anode nut and remove the rod.

5. Depending on how tight the anode rod is, you may need to use a little force to loosen it. We don’t do ours up so tight that it’s almost impossible to undo the next time.

6. Turn the anode rod anticlockwise until you feel the rod loosen and is easy to pull out.

7. Step back as you take the rod out, as water may splash about.

8. Now check the anode rod to see just how far it has corroded. Anywhere between 50% - 75% corroded is the best time to replace it.

Replacing or return the existing rod

1. Using plumbers thread tape, cover the anode rods’ thread from top to bottom. This will help to create a seal when the anode rod is returned to the tank.

2. Put the anode rod back into the tank in the opening you removed one from.

3. Tighten the rod in a clockwise motion until you are happy it will not leak water once the pump has power reinstated.

4. Return power supply to the water tank and the hot water system.

5. Go back inside the caravan and run the tap to remove air from the lines. Once the water runs without spluttering, you can turn the tap off.

6. Return to the hot water system door on the outside of the caravan and check for water leaks from the anode position.

7. If you find any leaks, tighten a little more. Once there are no leaks, the job is done for another 6 months.

It may pay you to keep a note of the date you have completed this job, to ensure you are regular with it, every 6 months. The rod may not actually need replacing each time, however checking it will allow you to decide if it needs to be done. Prevention is far cheaper than the cure!

Being proactive in caring for your Anode Rod, will ensure your Anode Rod will take care of your hot water system.

We hope this will help you in maintaining your caravan hot water system.

You can view our step by step instructional video on YouTube here