You know all those appliance manuals that came with you RV? Dig them out from under the bed and read them, at least once a year. It will remind you of certain things you need to maintain to keep your rig in prime operating condition.
Take for instance the water heater. It has an easily accessible anode rod that should be replaced at least annually. All RV water heaters are protected by this magnesium or aluminum anode to prolong the life of the tank by absorbing the corrosive action of hot water. Basically, it will corrode before the tank does. And if it corrodes entirely, it can no longer do its job.
This is just one of those little things we forgot all about. And we are not alone. But it is also one of the most simple items on the honey-do list of any RVer. Just make sure the hot water has been turned off for a while or you may get scalded, and that your hose is disconnected so the system is not pressurized.
Then release any pressure in the water heater tank by pulling its relief valve. Now get yourself a deep socket – the rod in our Suburban water heater has 1 1/16″ head – and loosen the threaded anode rod at the bottom of the water heater. (Yes, from outside your rig.) Let all the water drain and flush out any debris with a hose. this took me a while because we had accumulated quite a bit of debris as you can see by how our old anode looked.
Replacement anode rods can be found at any RV parts counter or service center. To prevent leakage, apply teflon tape to the threads before screwing in the new anode. Make sure it is screwed in straight and secure, fill the tank, run a faucet to allow any trapped air to escape, turn on the heater, and you’re set for another few months. Or at least until you remember you forgot all about the water heater anode again.