How To Sanitize an RV Water System

Updated! We show you how to thoroughly sanitize both hot and cold sides of your RV’s fresh water system.

Don’t have a winterizing kit? No problem! Here’s the trick we use:

Want to sanitize the cold water side only? Here’s how:

Click here to find Slunky sewer hose support:

We’ve been drinking the water from our RV’s fresh water tank for over a decade without a problem. It’s perfectly safe to do, as long as you sanitize your fresh water system periodically. We do ours about twice a year (keep in mind that we’re full-timers… those who store their RV all winter should be fine sanitizing once a year, in the spring).

Clean, safe, sanitary drinking water is a breeze when you take a few basic steps to manage the fresh water system on your motorhome, travel trailer of fifth wheel. Fresh, drinkable, potable H2O doesn’t only come from bottled water, but right from your RV’s tank, saving money and plastic in the process.

We’ll show you how to use bleach to kill any bacteria that may be present in your camper’s water system, and have all the safe drinking water you need.

If you saw the first video we made on this topic over two years ago, we only sanitized the cold water lines. That’s because the primary purpose of sanitizing is to make the water safe to drink. Since a lot of people asked about sanitizing the hot side of the system as well, we’re going to do both hot and cold sides today.

You can see the original video here:

If at all possible, the deal time to do this is on a day when you’re planning to take a long drive, preferably down some pretty twisty roads. This will agitate the water in the tank, helping to clean it as you drive, and make sure the top of the tank gets splashed too.

Since we’ll be doing some tank flushing as part of the process, your trip should ideally take you from one full hook-up RV park to another one, neither of which should have drought or water use restrictions.

It’s particularly important to end your drive at an RV park with water hook-ups, since you’ll be arriving with a tank full of bleachy water.

The only supplies we’ll need for this job are some bleach, a 1-gallon pitcher and an old measuring cup.

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The intro music is my own piano performance of Scott Joplin’s Maple Leaf Rag from 1899.

Full-Time RVers since April 11, 2003, we share DIY (do it yourself) RV maintenance, repair, travel, upgrade and operational tips & tricks.

While we’re not RV technicians, we’re very mechanically inclined and have learned a lot about RV systems over the years. We’ve handled most of our own minor service, maintenance and upgrade work on both of our RVs.

We meet lots of newer RVers who are eager to learn some basics about using, maintaining and caring for their rigs. After more than a decade on the road, we’re happy to share what we’ve learned (some of it the hard way). 😉 We hope our experience can help other RVers go DIY, saving time & money while experiencing the satisfaction of a job well done. We’re handy RVers, not professional technicians. We’re happy with the techniques and products we use, but be sure to confirm that all methods and materials you use are compatible with your equipment and abilities. Regardless of what we recommend, consult a professional if you’re unsure about working on your RV. Any task you perform or product you purchase based on any information we provide is strictly at your own risk.

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Captain Quirk says:

What model of RV do you have that has a 105-gallon tank?

pbcoupons says:

Thank you for this video.  We are newer  to RVing and used this last year to sanitize our on board water and again this year.  Love your updates!  Regards

Mzdiana says:

If you don’t clean your system, you can get a bug in your gut that mimics an ulcer. It’s called h.pylori, and can be very uncomfortable. You can be tested the first time with a simple blood test, and it can be treated with antibiotics. If you get it again, a blood test doesn’t work as it always shows positive in your blood, you’ll have to have a biopsy done via a endoscopy.

Keep your tank sanitized and use a filter.

bucsfan116 says:

How do you add bleach if you don’t have a winterizing kit on your RV

Sharon Lavoie says:

Rv geeks, is it dangerous to ingest minerals from the magnesium anode in the rvs water heater?

boliskmail says:

Ok. . .I’m by no means a chemist. . .

I have a well at my house. . .and I’ve been instructed by several contractors to NEVER use household bleach for sanitizing potable water supplies or containers. . .as they can and do often contain heavy metals and such. There are sanitizing products specifically designed for potable water. ..such as Well Safe. . .that may be a more safe option. Just a friendly FYI.

Ray J says:

We never drink from our tank but do sanitize twice a year. We filter all drinking water through a Berkey counter top filter, even store bought water can be problematic … safe travels.

Chambers1831 says:

I want to drink that bleach.

Kay Love says:

Great tip

Joey Jetson says:

We prefer to Sanitize both the hot and cold site.  Figure on when washing and especially rinsing dishes and glassware we like to feel that the water has a better chance of being Sanitized.
Thanks for the info and all the video’s.

Z Shark says:

Thanks for the great info.. I’m going to flush my Xplorer out tomorrow 🙂

PaleoAthletics says:

I’ve heard bleach is bad for the plastic and rubber and to use Hydrogen Peroxide instead. What do you think about this?

jcherokee says:

I have access to my parents Flair Class A that has been stored in an inclosed steel garage with concrete floor for three years. It was winterized well, temps where it is stored are 80’s in the summer and 40’s to below freezing during the winter. How well do you think this process would sanitize the fresh water tank? I don’t have access to the manuals so I haven’t been able to review the manufacturers recommendations yet. It will most likely be spring 2016 before I pull it out of storage so I’d also appreciate any insight you have on long term storage… As well as things I might want to take care of before this next winter is upon us…

Kristen Wakeham says:

Ok, I’m feeling really stupid or maybe just deaf. I thought the audio said 1/4 cup of bleach per gallon of tank capacity, but the equation on the screen had minus 7 in it. What was the minus 7 for?

Cecil Bailey says:

I’ve owned 6 rv’s with winterizing kits and none of them would put chemicals in the holding tank, the suction side of the pump is after the tank so how could bleach be put in the tank with the winterizing kjt? I’ve always had to disconnect the hose from the water source empty the fresh water hose fill it with measured amount of bleach turn on the tank fill valve reconnect the water hose to source and allow the bleach to enter the tank while being mixed with the water fill pressure. If you understand it different please reply we all learn from one another.

v2joecr says:

With the type of faucets you had in the RV you were using the hot and cold water will mix so closing water to the water heater was a good idea. You either need valves that you turn off at each faucet, 1 way valves, or to turn the water off to the water heater as you did.

John Moody says:

This would be pretty cool, but I’ve seen what even diluted bleach can do to the plastics that black and gray water tanks are made out of.  Breaks that plastics down like nobody’s business.  Ever seen a black tank explode going down the road?  You don’t wanna’ be behind one.  Looks like a recipe for disaster.

justanothervote says:

Question for you….How do I sanitize my Rv since it doesn’t have a winterizing kit, or gravity fill? It does have an inside filter (I”ve seen the melthod of putting the bleach in the filter housing after taking the filter out, but that won’t work for me because mine is located unter the sink and wouldnt sanitize the whole system.) I’m thinking I’m going to just pour bleach into my water intake hose, and them hook it up and turn on the water, but that sounds messy and somewhat primitave lol! Does anyone have a better Idea?

Butch Evans says:

A couple of comments: First, why would you not want to sanitize your water heater? There are times you will use hot water for making tea or instant coffee so I want my tank cleaned also. Just because you don’t run antifreeze through it does not mean you shouldn’t sanitize it.

Second: I really don’t understand how you are using the winterize setup to sanitize your fresh water tank. When you pull antifreeze into your system through the winterizing setup this does not take the antifreeze to the fresh water tank. It only takes it into the lines in you MH. How does this sanitize your fresh water tank, it only gets the chlorine into the plumbing from the pickup tube to the faucets.

Just curious

Michael G. Gartman says:

Thanks for the info, but the piano music is annoying.

Jack Brown says:

Probably a silly question but I’m new to RVing. Wouldn’t it be better to do the long, twisty driveto a new RV park with a full fresh water tank of water and bleach solution  first? With a full fresh water tank of the bleach and water solution that’s been jostled around for at least an hour and then left in the fresh water tank for 4 to 8 hours you’re guaranteed to completely sanitize the fresh water tank.

Then you can use the water pump to sanitize the water lines to the faucets, shower, bath, etc.

RV Van Life says:

Hi RVG, Isn’t there a kind of a supplement issue to this topic where an even less concentrated amount of bleach is used on an ongoing basis?; my water pump instructions [ as I thought I understood it ] said to always put in 5 drops of bleach to every 5 gal of water every time the tanks are filled ,maybe as a kind of way to keep contamination at bay, Iv’e always run across these 2 instructions but never both issues mentioned within the same material, Do you also do the 5 drops thing beyond the sanitizing?


newbie here , this is my first rv in a long time , i just bought a 98 mallard fleetwood but they dont make them anymore ..its in great cond but i have hooked up to the water and the kitchen sink has a smell like its sewer or just bad…the rv place didnt give me a walk around they said it could be 2 weeks so i just said ill learn on my own..i dont even have the owers manual either and its hard to get one…can you give me some pointers please

chris crory says:

Our 5th Wheel trailer is parked in a place we go to only on weekends 6 months of the year and it never moves. (It has a snow roof to get through the winter months!) Anyway, any other ideas to get the “moving” action in the tank if we can’t move the rig?

Jody Raines says:

Thank you for this valuable information.  Its great to have the video to follow before attempting this by myself…

Steffon Liford says:

be sure to fill & drain fresh watet tank until you no longer smell bleach. they said depending on how strong you made the solution it could take 2-3 times.

Derek Thompson says:

Love the visual coming down into YV on Old Woman Springs Road. Man, I miss the desert!!

tl K says:

I commented a while back about sanitizing the lines of a fifth wheel we moved into.
We tried to sanitize the lines but learned that our freshwater tank is damaged and will not hold water. We use city water, but the rv is old and I am wondering if it is safe to use the water for dishes, etc, without running bleach through the system. Our RV repairman said we should be fine, but I was wondering if there is any way to clean the lines without pumping a bleach solution from the tank?

Walter Combs says:

Curiosity question… Is that long twisty road Old Woman Springs traveling towards Joshua Tree National Park?

David Lisauskas says:

Great information as always guys!! You have the best RV how to videos out there! We made a modification to the process by installing a press-fit connector on the end of the low point pex tube and another fitting to fit the inside diameter of a cheap garden hose. Since it is low pressure no need for a hose clamp. I just pull the hose off when we are done. Then we can drain directly into the sewer drain as opposed to having to run the pump through the grey tank and then purge. Thanx for all the great videos!

George Bowman says:

Great video, thanks for posting

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