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If you’ve seen my first, or second experiment with the clear RV black tank, you’re probably guessing that I’m not one to just accept the conventional wisdom on RV maintenance topics. You’d be right.

Today, I’m tackling the RV water heater. Most sources will tell you that you need to rinse out the water heater at least once a year. It seems like reasonable advice, and a way to flush out any sediment, or other organic matter that may find its way in there. But I’ll be honest – I’ve not done that for well over two years now! So when I finally got around to rinsing out the tank, I took a probe camera to it so I could see just how bad things had gotten in there…


I’ll be honest, I was pleasantly surprised. We live in Utah, and have fairly hard water, so I was expecting to see a lot of scale and buildup inside the water heater tank. But actually, it wasn’t that bad at all. Sure, I saw a little pitting:


And I could see something that looked like rust (but the tank is aluminum, so I know it’s not rust).


But overall, nothing that had me worried at all. Certainly no mold, slime, sludge, or anything like that. Though I did see several pipes inside and I was able to view the electric heating elements as well.


Now – our water heater is an Atwood, which has an aluminum tank. So there’s no anode that I need to replace. If you have a Suburban, things may look differently for you, and you’ll certainly want to at least replace the anode rod every year. Also, it’s pretty arid in Utah – we don’t generally have to worry about mildew, for example. AND, I generally only fill up with treated culinary water. If you have well water, things may look differently inside that tank. But overall, for my usage patterns, and my tank, rinsing for 15 minutes every year would probably be overkill.

Rinsing out your water heater every year is still probably solid advice. But in my case, it was good to find out that I wasn’t in as dire of a situation as the conventional wisdom would have led me to believe.


I just re-read this article, and if it sounds like I’m recommending that you never flush out your water heater tank, then you’ve got the wrong impression.  I went outside the next day to the spot where I rinsed the tank out, and I found what you see below:

Water Heater Sediment

That’s a sand-like sediment that I did flush out of the water heater.  So obviously, rinsing it out did some good, and did remove that bit of sediment after at least two years of use.  So – to be clear – my advice is … DO rinse out your water heater tank.  Once a year, or when you sanitize the water system is a good frequency.  But if you forget one year – the world probably isn’t going to end.  Cheers!