Did you know that replacing the anode rod in your caravan hot water system is something that you should be doing periodically? Neither did I before becoming a caravan owner myself. There’s always something new to learn as a caravanner!
Replacing the sacrificial anode rod is something that needs to be done every six to twelve months in your caravan. The sacrificial anode is a vital part of your caravan hot water system, which is designed to prevent rust and corrosion inside your water heater. Changing the anode is a fairly simple task, which you can DIY at home with a few basic tools and knowledge.
Here are the steps for how to change a caravan anode rod:
- Turn the power off
- Switch the water off
- Release the pressure
- Remove the anode
- Flush & clean the tank
- Add thread tape to new anode
- Install new anode
- Turn water on & ‘bleed’ tank
- Turn power & gas back on
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What is a Sacrificial Anode Rod?
The Sacrificial Anode Rod is a part installed in your caravan hot water system, which does just as its name suggests. It quite literally ‘sacrifices’ itself so as to prevent corrosion within your hot water system.
As the anode rod is made of a softer metal (magnesium) than the water tank, it bears the corrosion. As this part is designed to break down, it only makes sense that you’ll need to replace the anode every so often, essentially extending the life of your caravan hot water tank.
Hot water tanks that are made from stainless steel do not corrode, therefore do not have an anode rod. However, the suburban hot water system, which is one of the most widely used in caravans and RVs in Australia, is made from a different metal that will corrode if you don’t keep on top of your anode rod replacements.
How Often Should You Replace the Anode in a Caravan?
You should be checking the anode in your caravan every six months to see if it needs to be replaced.
Along with that, if you’re about to head off on a big trip, especially heading off the beaten track or into the outback, you should double check that your anode still has plenty of life left in it.
Once your anode has corroded to about 50% of its original diameter – it’s time to change it. You can leave it to a maximum of 75% of it’s original diameter, but letting it go beyond that (or overextending the anode’s life regularly) will only harm your hot water tank.
The wear of your anode can be very dependent on the quality of water that is being run through the hot water system. Travelling through areas with ‘harder’ water (higher concentration of calcium and magnesium ions) will work through your anode at a faster rate.
How to Change an Anode Rod in a Caravan Hot Water System
Replacing the Anode in your caravan hot water system is a simple task, which you can do yourself at home if you’re handy with basic tools. You don’t need a lot of equipment for the job, so let’s get into it.
Tools required for changing an anode
These are the tools that we use for changing the anode. Yours may vary a little.
- 27mm Socket
- New Anode Rod
- Ratchet or Extension Ratchet
- Wire with brush end
- Plumber’s Teflon Thread Tape
Steps for Changing the Caravan Hot Water Anode
Here is the step-by-step guide on how to change the anode rod in your caravan hot water system.
STEP 1 – Turn the power off
The first step is to switch off the power to your hot water heater well and truly before you’re ready to change the anode. You need to give the water time to cool down so that you don’t burn yourself when you remove it.
Below are the instructions depending on whether you’re on mains power or gas at the time.
- 240 volt – switch off the supply to the hot water system and unplug the 240 volt power to the system
- Gas – completely turn the gas supply off at the bottles
Let the water in the tank cool right down to avoid burns.
STEP 2 – Switch the water off
If you’re on tank water, you’ll need to switch the water pump off inside the van. Be aware that this process will use a fair bit of water, so you’re better off doing it when you’re hooked up to town water.
If you’re on mains water, go and switch the water tap off.
STEP 3 – Release the pressure
Next you need to release the pressure in your tank by turning on the hot water tap inside your caravan. Leave it on until the water stops running to be sure that the tank has depressurised.
Then head back outside to where you access your hot water system and open the pressure relief valve, to make sure there is no pressure left in the tank.
STEP 4 – Remove the anode
Click the socket and ratchet together, then attach the socket to the anode end and turn it anti-clockwise to undo. You may have to use a bit of force to loosen the anode, especially if it hasn’t been inspected or changed for a while.
Once the it’s undone, you can pull out the anode. As you remove it, water will gush out, so grab a bucket or just let it water the grass.
If your anode is still looking really good, you’ll still need to flush the tank out, but you can put the anode aside to reinstall.
STEP 5 – Flush & clean the tank
Now it’s time to flush all of the gunk and anode residue out of the tank. For this, you need to turn the mains water (or pump) back on so that the water will keep flushing the tank.
Don’t turn the power back on just yet because you don’t want the water to start heating up.
This is where you can use the brush on the end of some wire to get in there and give the tank a good clean out.
Once the water runs clear, go and switch the mains water back off.
STEP 6 – Apply thread tape to the new anode
While your tank finishes emptying, you can go ahead and add some plumber’s thread tape to the thread of the new anode. You may find that yours has come pre-wound with tape, but more often than not, you’ll need to add your own.
The thread tape helps to seal the thread and reduce the chance of any future leaks. If you’re reinstalling the old anode, you’ll still need to apply some thread tape.
If you’re not sure how to add thread tape to the anode, skip to 4.27mins in the video down below to see how it’s done.
STEP 7 – Install new anode
Now you can slide the new anode into the hot water system, turning it clockwise to tighten with your fingers. Then you can tighten it even further with the socket.
The anode might not tighten all the way to the end of the thread, so be careful not to over-tighten or cross-thread it.
Turn the water on & ‘bleed’ the tank
Now that the anode has been installed, go and turn your water back on and allow the tank to fill itself back up. Check for leaks around the thread of the anode and give it a little tighten if necessary.
Turn on one hot water tap inside the van until the water runs through the tap, then turn it off.
Head back outside to the hot water system and ‘bleed’ the air out of the tank by opening the pressure relief valve until the water runs continuously.
Turn the power & gas back on
Replacing the anode in the caravan has been successfully completed. You can now switch the 240 volt power back on and plug the hot water system back in (if you unplugged it). You may now also turn the gas back on at the bottles if applicable.
*Note: Don’t ever leave the power switched on while the water tank is empty or turn the power back on before letting the tank fill back up with water – you will burn out the element.
Winter Tip
You can use the process here for emptying out your caravan hot water system in winter if you wish. This is especially useful if being stored in very cold temperatures where water freezing is a concern. Just remember to always refill the hot water tank before turning the power on.
▶️ VIDEO: Replacing the Anode Rod in a Suburban Hot Water System
Check out the video below to see exactly how to change the anode rod in a Suburban hot water system.
The Suburban water heaters are very popular in Australian caravans, campers and RVs. But even if you don’t have the Suburban system, this will give you a good visual guide on how to replace your own anode at home.
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Hi my thoughts on anode for these heaters.
1 Make sure you buy the correct metal type for your heater.
2 If you place a small 3/8 diam wooden dow into heater you can feel a pipe at rear of heater inline with where the anode fits if anode is too long it will damage this pipe due to vibration. There are various lengths of anodes.
3 A lot of sealing tape will insulate the anode and stop it from working properly. Tape needs to be placed only at rear of thread so that there is a metal to metal connection with the thread and heater.
Just my 10 cents worth that may help others from having problems.
Cheers Dean
Thanks Dean!