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Flushing an Atwood RV Water Heater

Flushing an Atwood RV Water Heater

 

We demonstrate how to thoroughly flush and clean an RV water heater.

UPDATE – April 3, 2012: Regarding our use of an after-market anode rod. There are questions about which metal to use – magnesium, aluminum or zinc. As we mentioned in the video, we only chose this particular anode due to the extreme difficulty we had removing the original, despite the fact that it is a different material than the original rod. We’ve now inspected it after a year and are not happy that it did not decay as expected this year (did not decay at all), and are concerned it isn’t protecting the tank properly. After hearing from two friends who also have Suburban units, who removed their anodes without much trouble, we’re going back to the OEM rod with no drain, and will be updating the video when we do.

UPDATE — Sept 22, 2013: UPDATE! THE ANODE ROD VERDICT IS IN!
WATCH IT HERE!

Rust, lime scale and other debris can build up in the hot water tank on your motorhome, travel trailer or 5th wheel. Left alone, this can shorten the useful life of your water heater. Simple annual maintenance and care of your RV’s hot water system will save you money by extending the life of the heater.

We recently flushed the Suburban water heater on our Newmar, so rather than do it again, we’ve borrowed our friends’ Atwood water heater to demonstrate how to do it.

Only a few simple items are required, including a wrench to remove the drain plug or anode rod, a tank flush wand, and some white vinegar (1/2 gallon for every gallon of tank capacity). If you have a Suburban brand water heater, be sure to have a new replacement anode rod on hand as well (magnesium, aluminum or zinc/aluminum).

The small amount of time required to do this simple but essential maintenance will pay for itself with years of extra service from your RV’s hot water heater.


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Pat Tighe

Sunday 10th of October 2021

Good morning, just a quick question about the hot water tank rinse. You use a plastic plug instead of using the anode rod. To save 35 dollars why can’t I just cut the anode rod off of the nut and use that instead of a plastic nut? Thank you

TheRVgeeks

Sunday 10th of October 2021

Hi Pat! We’re not actually using a plastic plug to save money on this one. It’s just that Atwood heaters don’t require anodes at all because of their aluminum tanks, and come from the factory with a plastic plug. We really like the fact that Atwood heaters don’t have to mess with anodes at all because of that, and the plastic plug simply goes along with the aluminum tank. Hope that answers your question!

Marc Mason

Friday 8th of December 2017

I wanted to let you guys know I love your instructional videos! You guys are my first "Go To" site if I have a question about RV Maintenance and equipment! Thanks for the Atwood video it was very helpful! A question I have is about the Divert setting - since I don't have something labeled "Divert" is that the same as a winterizing setting? This should pull the fluid into the coach and if I don't bypass the water heater it should fill it first - correct?

Do you mind if I ask another question unrelated to the topic above - I noticed you guys lean your engine with a power sprayer. Do you reduce the pressure and should the engine be running or off? I have a Cummins 300 HP Diesel and to my knowledge has never been cleaned - If you guys have a video on how to clean an engine I would love to see that!!!

Thanks for all you do to help us Newbie's feel comfortable with our Coach!!!

Marc Garland, TX

TheRVgeeks

Friday 8th of December 2017

Thanks, Marc! That's really nice to hear and we appreciate you saying that! Made our day!

On the water heater flushing... what we are using to get the vinegar into the system is a "Winterizing Kit" (came installed on our RV, but you can retrofit one if your RV doesn't have one). It's designed to allow you to pull antifreeze into your plumbing lines using the water pump. We ALSO have a set of "Water Heater Bypass" valves. These isolate the water heater from the fresh water system... so that when you're using the "Winterizing Kit" to suck antifreeze into the system, none goes into the water heater (so you don't have to buy 20 gallons of antifreeze!!)!

So you don't need a "Divert" (or "Water Heater Bypass") valve to flush the water heater... you need a "Winterizing Kit". And since you don't have a "Divert" valve... you are correct... using your "Winterizing Kit" will allow the vinegar to fill the empty water heater.

As for pressure washing our engine, we don't turn the pressure down, but our pressure washer is only a 1500 PSI unit, so it's not that powerful. We ARE careful with the spray and keep the nozzle back from hoses/belts/wires and anything else that could be damaged by the water pressure. And because we've ALWAYS kept our engine clean, we don't have much (if any) "gunk" in there that NEEDS heavy power washing to remove it. We're mostly washing off dust! If your engine is very dirty, you may want to take it in to a shop to have them steam clean it to remove all the heavy oil and buildup first, so that you can just "maintain" it by washing off the light dust, etc.

One other note - about 5 years ago, our engine developed an oil leak that required a week in the shop for them to address it. As part of the repair, they had to power wash the engine several times so that they could find (and confirm repair of) the leak. We can't say for certain, but it appeared they were using a MUCH more powerful power washer than we have, and they didn't seem to have any concerns about harming anything. This was a Cummins engine shop, so we're sure that if blasting the engine with high pressure water would cause a problem, they would know better than to do it. And nothing they did back there caused any harm. Now maybe they're aware of certain areas to avoid blasting too closely. So, if we were using very high power water (like at a DIY car wash) we would just be EXTRA careful to avoid aiming too closely (or too long) at any one area of the engine.

For what it's worth, we power wash our car's engine all the time, too... and, since the advent of fuel injection & electronic ignition, there doesn't seem to be anything to worry about.

Hope this helps!

Steve Pratt

Tuesday 24th of October 2017

One more comment while I await your guidance... The line that I can disconnect from the water pump and replace with my "sucking hose" is the line that comes from the FW tank. So (I think) I'll be completely bypassing the FW tank and sucking straight into the Hot Water Tank? If that's true, what setting do the valves need to be set to in order to fill the hot water tank with the 5 gallons of city water? Remember, I've already winterized and have blown my lines out. I suppose I could suck 5 more gallons of water in the HWT from my empty vinegar jugs, just filled with water?

TheRVgeeks

Tuesday 24th of October 2017

Hey Steve... our replies must be passing like ships in the night. See our reply back to your comment below. But in answer to your follow-up... yes, it indeed sounds like your winterizing hose attachment for your pump means that it is completely bypassing the fresh water tank. Attaching that hose means the water pump's "supply" will be coming from whatever container you stick the other end of that hose into. And, yes, that means you could add the remainder of the water needed to fill your tank by just putting fresh water into the vinegar containers.

BUT... doing this will likely result in vinegar & water ending up in your plumbing lines, undoing your winterizing. In normal conditions, when your plumbing lines are full of water and everything is turned off, the empty water heater is the only place for the vinegar to go to when you use your pump and the winterizing hose attachment. But since you've already blown out your lines... that means the vinegar can go everywhere. Sure, some of it will end up in your water heater, but a lot of it will also get pumped throughout the rest of your plumbing. There is no combination of settings on valves that can create a direct path from your water pump to JUST your water heater when the rest of the plumbing is empty, too.

That's why we're suggesting that you may want to hold off on the vinegar flush of your water heater until the spring when you've de-winterized the plumbing. With all of the rest of the pipes full of water, the water heater is (effectively) the only place the vinegar can go.

Hope this helps/makes sense.

Steve Pratt

Tuesday 24th of October 2017

Good afternoon guys. Love your videos. I have a 2011 Tiffin with a Suburban water heater. I don't have a "divert" valve. I also JUST winterized and blew out all my water lines, and would prefer to just import water and vinegar into the Hot Water Tank.

Is your "divert" valve the same as my "Hot Water Bypass" valve? I do have an optional hose that I can connect to the water pump for importing antifreeze. What exactly would my steps be after rinsing out the tank and replacing the plug?

I have 2 valves in my wet bay: - City Water/Tank Fill - Hot Water Bypass/Normal Flow

As I understand it, If it's set to City Water... the water goes straight into the Hot Water Tank... Is that correct? Further, If I have the other valve set to Hot Water Bypass, the city water goes straight into the Fresh Water Tank? Is that correct?

So... when importing the Vinegar, would I have the valves set for: - City Water - Normal Flow

Thanks, Steve

TheRVgeeks

Tuesday 24th of October 2017

Hi Steve. Keeping in mind that we have no 1st-hand experience with Tiffins and their plumbing set-up, if we have it right, our "divert" valve isn't the same as your "Hot Water Bypass" but rather the same as your optional hose for importing anti-freeze. We'd suggest that your best bet might be to wait until spring to flush your water heater, because we don't think you can do the job without getting water into your plumbing lines. When you do go ahead and flush, and the tank is empty and it's time to add vinegar, the water heater bypass should be in "normal" mode and and the city water/tank fill valve should be in "city water" mode. Then you attach the optional winterizing hose to your pump (turning any valves necessary to activate/use it). Put the other end of that hose into the vinegar bottle(s), and turn on the pump. Since the water heater is empty, and the valves are in the "normal" position, the vinegar will be pumped into the water heater, since it's empty, and therefore the first available void for liquid to go into. Hope this is clear, and accurate for your system.

Shawn Wyss

Monday 22nd of May 2017

Good evening. We just purchased our first camper trailer. Unfortunately, we need a new water heater. I was wondering if you have experimented with the tankless water heaters for RV's? I found this one on Amazon and would like your thoughts on it.

https://www.amazon.com/gp/product/B01D7M7CT4/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=A3NENKYHSF56AK#HLCXComparisonWidget_feature_div

I like the efficiency of not heating water until you need it.

TheRVgeeks

Monday 22nd of May 2017

Hi Shawn! First, we have to be clear that we have zero experience with this type of water heater. Our concern would be how well they work when not hooked up to water and sewer, where we'd think the extremely low water flow typical with dry camping would be insufficient to get any hot water up without running more than needed otherwise, which would use up valuable fresh water and fill the gray tank faster. If your plan is to stay fully hooked up, the reviews do seem positive on this Amazon listing. We'd suggest getting a wider range of experienced opinions by posting your question in the user forums on iRV2. It's free to sign up and post (there might already be threads on this topic) at http://irv2.com/forums We're sure there are RVers out there who can shed some details from experience, both on the grid, and dry camping, about how well these work in various situations.

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