Skip to Content

How to sanitize your RV fresh water tanks

| Updated Apr 9, 2014

Yuck. Nothing tastes worse that the first sip of water through a just de-winterized RV's plumbing system on the first trip of the year. That's why it is important to sanitize that fresh water tank. And for that, there are lots of different approaches.

Everybody seems to have their favorite way of sanitizing the fresh water system.

cleanwaterRoadtrek Motorhomes has a suggested way, though. Here it is, how to sanitize your fresh water tanks, lifted from the instruction manual for the eTrek we use. There are similar instructions for all Roadtrek models. Find yours by clicking to and then reading the section on de-winterizing.

Some people will disagree with this and think it overkill. Others will say it's not enough. But for me, this is what I plan to do.

Note: If you follow this completely, it takes a lot of time, ideally a couple of days at least. And this is for the fresh water system. Your hot water system also needs to be de-winterized. But since there are so many differences in the way the different models heat water, you can look up your recommendations in the manual specific to your vehicle.

Roadtrek suggests a two step fresh water sensitization process:

First step

You will need 2 gallons of water and 1 cup of fresh bleach. (Bleach loses its potency over time; always start with bleach that is less than 6 months old.)

  • Mix up two gallons of water and one cup of chlorine bleach. Add to the fresh water fill. Allow a few minutes to drain into exterior tank.
  • This is a good time to get some stuff for spring cleaning of your Roadtrek, so drive around for an hour. Let it sit for a couple more hours. The driving sloshes it around in the tank. That is good.
  • When you get home again, open the drain valve and drain both tanks.
This kills any bacteria in the tanks before you distribute them through the entire water system.
Second step
  • Mix 1/2 cup of chlorine with 2 gallons of water and pour into fresh water fill.
  • Fill fresh water tank about 1/2 full.
  • Add 1/2 cup of chlorine and fill fresh water tank about 3/4 full.
  • Turn on water pump, circulate through entire system.
  • Run water out of every faucet and shower head until you smell chlorine.
  • With the water pump on, open the city water valve, and let the pump push water through the fill line for a minute or so.
  • Run the galley faucet for several minutes. If you smell chlorine, your system is safe to use. If you do not smell chlorine or your water is foamy, or has a pungent odor, repeat this step.
  • Drain completely, fill fresh water tank with clean water, run all faucets for 2-3 minutes each.
  • To help get rid of the residual chlorine smell, pour a cup of vinegar into the fresh water tank, fill, let sit for a few hours, run the faucets for a minute or so apiece, drain the tank to ground, and refill with fresh water.
There you go. Let us know how it works for you or what your process of sanitizing happens to be.

Mike Wendland

Published on 2014-04-09

Mike Wendland is a multiple Emmy-award-winning Journalist, Podcaster, YouTuber, and Blogger, who has traveled with his wife, Jennifer, all over North America in an RV, sharing adventures and reviewing RV, Camping, Outdoor, Travel and Tech Gear for the past 12 years. They are leading industry experts in RV living and have written 18 travel books.

9 Responses to “How to sanitize your RV fresh water tanks”

August 21, 2016at3:50 pm, geoB said:

The link for Roadtrek manuals is broken.

April 14, 2014at3:45 pm, Jeff Greenspan said:

I am sceptable about using chlorine bleach. It has a reputation for eating rubber gaskets. How about baking soda instead? Or vodka (lol) to kill the germs?

April 13, 2014at5:14 pm, Alex said:

Do the same last 10 Years.
Thank you Mike for good advise. It works !!!

April 10, 2014at2:42 am, Edna Plett said:

Steve Plett

April 09, 2014at10:24 pm, Rose Aaserude said:

I printed & saved this too….

April 09, 2014at6:16 pm, Corey Cottom said:

Steven Tyler Cottom

April 09, 2014at5:52 pm, Meryl and Me Hit the Road said:

We have never had to use vinegar to rid the system of the bleach smell – and would rather not taste the vinegar taste that will remain in the tanks after flushing. We have had very little bleach odor left after several flushings with fresh water in the tanks including the hot water heater tank (most of the odor is noticed with hot water as that tank needs its own draining to fully clear it) and during the first trip of the season that slight odor is completely gone.

April 09, 2014at3:06 pm, Dorothy Smith said:

printed and saved thank you

April 09, 2014at10:22 am, Campskunk said:

being a fulltimer, my system doesn’t sit stagnant for long. i still go through the sanitizing procedure twice a year, though, because even though the water’s flowing all the time, that doesn’t mean things can’t grow on the tank surfaces and inside the lines. even harmless organisms like many algaes aren’t all that pleasant to see swimming around in your drinking water.

Comments are closed.

Back to top