Wednesday, November 29, 2023


How to keep your RV’s fresh water tank fresh

Do not assume your RV’s fresh water will stay safe and fresh like at home. Contaminated water is extremely dangerous. As RVers, we must not only deal with a water system that hasn’t been used for some time, but we hook up to different sources and eventually contaminated water.

The most important step is to keep the fresh water system sanitized. At a minimum, sanitize it every spring or if you notice stale water or an odor.

Start by draining the water heater. Go to the outside compartment where it’s located. Remove the drain plug in the bottom left hand corner and open the pressure relief valve on top to assist in draining. CAUTION: Never drain the water heater when it’s hot or under pressure. Next, locate the low point water line drains for the hot water and the cold. This is the lowest point in the system. Open and let the water drain out.

Now, find the drain for the fresh water holding tank and empty it. Then turn the water pump on briefly to force out any remaining water. Do not let the pump continue once the water stops draining. Close all the drains. You have now removed most water from the system.

NOW TAKE A QUARTER CUP OF HOUSEHOLD BLEACH for every 15 gallons of water that your fresh water tank holds. Mix the bleach with water in a one-gallon container and pour it into the fresh water holding tank. Fill the fresh water tank almost completely full. Turn on the water pump, open all hot and cold faucets and run the water until you smell the bleach at each one. Close the faucets. If possible, drive the RV or pull the trailer so the water can move around to assist in cleaning the entire tank. Let it sit for at least 12 hours. Drain the entire system again and refill the fresh water tank with potable water.

Open all of the faucets and run the water until you no longer smell any bleach. You may need to repeat this process again to eliminate all signs of bleach from the system. Once that’s done, it is safe to use your water system.



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SDW (@guest_86193)
3 years ago

Better still, just drop by a swimming pool supply place and pic up a canister of CLOR BRITE
SANITIZER. One cup will sanitize a whole swimming pool. So all you need is a table spoon worth. It’s in granular form so you don’t have to worry about getting bleach on your clothes.
One canister will last a lifetime of RVing. I’ve been using the same canister for 12 years and
I’m not even half way down the canister.

Bob Weinfurt (@guest_86123)
3 years ago

Read the ingredients list to be sure the bleach you use is chlorine bleach. Even Clorox makes a non-chlorine bleach.

Robbie (@guest_85985)
3 years ago

If you use your directions of “Start by draining the water heater” without turning off the electricity, you’ll ruin the heating element in the hot water heater.

Montgomery Bonner (@guest_85883)
3 years ago

Studies indicate, the water tank stays “safe and healthy” for about 4-6 months, provided it’s not too hot. Personally, I never trust the water in the tank if it’s older than 45 days. So I sanitize it if the coach has sat (not being used type sitting) if over those days. If we are using it, especially long term, I do it every 6 months. Most public water systems are required to treat water to make it safe, but you never know, so safe and healthy is the watch word. Sanitization procedures are available online, or ask in most forums.

Irv (@guest_85902)
3 years ago

0nly 30 days without use for me

Sharon B (@guest_85910)
3 years ago

Every 6 months would not work in South Florida or in high heat areas. The sun and heat is brutal. I am a bleach person. That small amount of bleach will do wonders. Wash out really well and all should be ok. And it’s cheap. However, I will only dump bleached water in the dump station or at full hookups. Never in the BLM or other lands. That is sacred land for the wildlife. And never in the ocean.

Glen H Scofield (@guest_85882)
3 years ago

Another–equally effective way–is to sanitize your water system with swimming pool salt. It is just as effective as the bleach way, and because it’s swimming pool salt, it doesn’t leave that salty flavor that table salt leaves. I’ve used both methods with success, and I prefer the salt. Two to three tablespoons will do the trick. Like the bleach method, the key is aggressive rinsing to remove the unwanted flavor.

Chuck Dunn (@guest_85925)
3 years ago

First I’ve heard of this. I don’t like bleach. Tried it once and had the taste and smell for 6 months. Treat mine every two years, need it or not and I have never had stale tasting water.

Rick (@guest_87303)
3 years ago
Reply to  Chuck Dunn

Bleach is just a PIA. I have used Starbrite AQUA FRESH for a long time on power boats and now our RV. No Bleach!! Very simple

Walter Jones (@guest_85848)
3 years ago

Soft start is the way to go. DIY, easy install. Quiet and now my RV can run AC off 20 amp.

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