I'm sure many of you already know, but for those of you who don't - this mistake will cost you big time!
Not checking (and replacing, if needed) your hot water system anode rod every year. This applies to Suburban hot water systems, which are in found most of the caravans that I work on.
Suburban hot water system tanks are made of steel, which when filled with water would corrode. To prevent this corrosion, these hot water systems are equipped with a sacrificial anode rod, which will corrode instead of the tank itself. Most anodes tend to only last a year or two before they need replacing. I've replaced hundreds of hot water systems that could have been avoided if the customer had known about the anode!
To remove and check your anode, first make sure the caravan is disconnected from mains power, the gas operational switch is off, and turn off the water supply. Then, after making sure the system is cooled down, release the pressure out of the tank. To do this, turn the hot water tap on until no more water is flowing out. Now, to access the hot water system: drop down the service door on the exterior of your caravan, then unscrew the anode, which is at the bottom/middle of the system (this will require a 27mm socket). Be aware: although the pressure has been released, the anode still might pop out with the force of the water remaining in the tank. This is 22L of water that will drain out - so make sure you're outside.
Now, simply check your anode rod - if it's worn down like the above photo, you will need a new Suburban hot water system anode. When you replace it, make sure you use a thread tape NOT a liquid thread seal, which is made for permanent fixings.
It's very important to make sure your hot water tank is full before turning on power. To fill your tank, connect the water supply or turn your pump on. Now, open up the hot tap - once water is flowing out you know the tank is full.
Hope this article helped you and possibly saved you money in the future. Also, be sure to check out my other Top 5 Caravan Mistakes.