How Often To Sanitize RV Water Tank

How Often To Sanitize RV Water Tank

Published Date: September 22, 2020

Last Updated on April 19, 2023 by Camper Front

Knowing how often to sanitize your RV fresh water tank is very important. You can never be too sure of the type of water source you get your water from once you are out camping, even if you don’t drink it. You will be using the water for dishes, showers, or even cooking.

That’s why sanitizing your RV fresh water tank frequently is very important, and if you’re wondering how often you should sanitize RV fresh water tank, I’d say that it is recommended to sanitize your water tank at least twice a year and even more if you use the tank often.

How Often To Sanitize RV Water Tank

If you are one of those people who don’t drink their RV tank water, you may feel like there isn’t any need to sanitize it.

Well, think again! Contaminated water isn’t only harmful when drunk, using the water for other simple purposes like showering can expose you to skin infections. So you need to sanitize your water in order to keep yourself and your family safe.

While the sanitization process might not put up a huge cost, it’s going to require a substantial amount of your time as the process takes up several hours.

When sanitizing your water tank, you will need to also change the filters as they are needed for the removal of sand, dust, and rust.

You cannot do one without the other; you have to change the filter and sanitize the tank at the same time in order for the sanitization process to be complete. So how do you sanitize your water tank?

How to Sanitize Your RV Water Tank

How Often Should I Sanitize RV Water Tank

For this procedure, you are going to need a couple of items and approximately 12 hours to complete the process; here are the items you will need;

  • 1 New external water filter
  • 1 New internal water filter
  • Petroleum jelly
  • 1 Funnel with a flexible clear hose and stopper
  • 1 Water filter wrench
  • Chlorine bleach (unscented and non-gel); You will need approximately 1 oz. of bleach for every 8 gallons of water capacity
  • 1 Anode (if necessary)

Step-by-Step Procedure

Step 1

The first thing you want to do is turn off the water heater before you start to drain the freshwater system; draining your freshwater with your water heater on is going to damage your water heater, so you have to make sure you turn it off.

You can also decide to leave the water pump on to ensure you get all of the water out of the tank before you start sanitizing.

Step 2

Before using your newly bought or previously owned hose and funnel for this task, you need to sanitize them using a mixture of chlorine bleach and water. After about 15 minutes, you are ready to sanitize your tank.

To do this, you want to get the right measurement of bleach according to the size of your water tank.

You will need one ounce of bleach per eight gallons of water. Going by that measurement, You’ll need 1/4 cup of bleach for every 16 gallons of water in your freshwater tank.

But you do not add the bleach straight to the water tank; it has to be diluted, depending on the amount of bleach the size of your tank requires,

you want to take that amount of bleach and mix it with a gallon of water, then using your already sanitized funnel, you then pour the mixture into the freshwater tank.

If you have a bypass for the hot water tank, set it to normal use so the bleach mixture will circulate through the hot water tank.

Step 3

The next thing to do is Fill the Freshwater Tank with Potable Water until water flows from the overflow hose, so you know it’s full.

Then Pump It Through The System; this helps to ensure that the tank and the rest of the system get fully sanitized and that the bleach solution gets all the way through the system.

Turn off the freshwater supply and turn on your water pump, then Open all faucets, both hot and cold, in the RV until you smell bleach, and the water has circulated throughout, then Turn off the faucets.

Step 4

This next step is to Turn on the freshwater supply and add 3 or 4 gallons of fresh water to the freshwater tank, after which you let this solution sit for at least 12 hours or overnight. You don’t rush this process; else, your tank won’t be properly sanitized.

Step 5

We’ve almost come to the end of the process; after letting the bleach mixture sit in your tank for 12 hours or overnight, it is time to drain all the water out and refill it with fresh water and allow the water to circulate through the system with your water pump.

Flush out the water lines by opening the faucets and allowing the water to run until you no longer smell bleach. You may have to refill and rinse out the freshwater tank a second time if the smell of the bleach is still strong.

If, after a second rinse, you still smell bleach, you can flush the system with 1 quart of white vinegar and 5 gallons of water to rinse a third time. Some people prefer using a mixture of ½ cup of baking soda and a gallon of water in the freshwater tank until it flushes clean of bleach.

Step 6

This is the last and final step, Turn off the water supply and water pump and change the filter, but before you do so, you need to  Rub petroleum jelly on the new filter before replacing the old one as this makes it easier to remove and replace next time.

You may also need to flush the water heater, although many people do not do this, if we are going for a total cleanse, we might as well flush the water heater. There are many types of tanks with different configurations.

But in most cases, all you need to do is Turn off the power, then Turn off the water and the water pump as well. Open the relief valve to the water heater to prevent air pressure from building up and becoming combustible.

Then open the drain valve to the hot water tank so you can drain all the water. You may need to replace the anodes if they seem corroded. Close the relief valve and the drain valve.

You are now ready to refill and turn on the water source to the RV and enjoy a clean water tank.


Knowing how often to sanitize the RV water tank will enable you to keep a tab on the water tank and clean it when due, as these tanks can be home to various germs and bacteria. Even if you don’t drink the water, they have other means of affecting the health of you and your family.

When camping, you are going to be hours away from the nearest hospital or healthcare provider, so you want to make sure you stay as safe as possible.

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