RV Service in California [CUSTOM WAY] > FAQ > How to sanitize rv fresh water tank?

How to sanitize rv fresh water tank?

Sanitizing your RV’s fresh water tank is an essential maintenance task to ensure you have clean, safe drinking water while traveling. Over time, bacteria, mold, and algae can develop in the tank if it’s not regularly sanitized, leading to bad smells, unpleasant tastes, or even health risks. Fortunately, the process of sanitizing your RV’s water tank is straightforward and should be done at least once or twice a year.

Here’s a step-by-step guide on how to sanitize your RV fresh water tank:

Supplies You’ll Need:

  • Household bleach (unscented)
  • Fresh water hose
  • Measuring cup
  • Funnel (optional)
  • Clean water
  • A place to drain the water (like a designated RV dump station)

Step-by-Step Instructions:

1. Turn Off Your Water Heater

Before you begin, turn off your water heater. You don’t want the bleach solution entering your water heater as it can damage the heating element. Make sure the water in the heater has cooled down to avoid any safety hazards.

2. Drain the Fresh Water Tank

Completely drain your fresh water tank. Open the fresh water drain valve (usually located on the underside of the RV) and let all the old water flow out. You’ll want to make sure the tank is as empty as possible before sanitizing.

3. Prepare a Bleach Solution

The standard rule of thumb is to use 1/4 cup of bleach for every 15 gallons of water your fresh water tank holds. For example:

  • A 30-gallon tank would require 1/2 cup of bleach.
  • A 60-gallon tank would require 1 cup of bleach.

Mix the appropriate amount of bleach with a gallon of water in a container to dilute it. This ensures the bleach will disperse more evenly in your tank.

4. Pour the Bleach Solution into the Fresh Water Tank

Use a funnel to pour the bleach solution into your RV’s fresh water tank. To do this, you can use the gravity fill port or connect your water hose to the RV’s city water connection. Once the solution is inside, fill the rest of the tank with fresh water to dilute the bleach further.

5. Run the Bleach Solution Through Your Water Lines

After filling the tank, turn on the water pump and open all faucets (hot and cold) inside the RV until you smell bleach coming from each faucet. Don’t forget to include the shower, toilet, and outdoor faucets, if applicable. This step ensures that the bleach solution sanitizes not only the fresh water tank but also all the plumbing lines and fixtures.

6. Let the Solution Sit

Once you’ve run the bleach solution through the lines, let it sit in the tank and plumbing for 8 to 12 hours. This will allow the bleach to disinfect the entire water system thoroughly.

7. Drain the System

After the bleach solution has had time to sanitize the system, drain the entire fresh water tank and lines again. Open the fresh water drain valve and run all faucets to flush out the bleach solution.

8. Refill the Tank with Fresh Water

Refill your fresh water tank with clean, potable water. Then, run the water pump and open all faucets again to flush any remaining bleach from the lines. You may need to repeat this process a couple of times until the bleach smell disappears.

9. Test the Water

After flushing, taste the water to ensure there’s no bleach odor or taste. If you can still detect bleach, drain the tank and refill it with clean water again until the taste is completely gone.


Tips for Keeping Your Fresh Water Tank Clean:

  • Sanitize the Tank Regularly: Perform this sanitization process at least once every six months, or more often if you use your RV frequently or store it in humid areas.
  • Use a Water Filter: Adding a water filter between the water source and your RV can help reduce contaminants entering your fresh water tank.
  • Drain When Not in Use: Always drain the fresh water tank if you won’t be using your RV for a while to prevent bacteria and algae from growing in standing water.
  • Inspect for Leaks or Damage: While sanitizing, check your water system for leaks or any wear and tear that could compromise the system’s cleanliness.

Why Regular Sanitation is Important

Sanitizing your RV’s fresh water tank ensures that the water you use for drinking, cooking, and cleaning is free from harmful bacteria, mold, or algae. Neglecting this essential task can lead to unpleasant water tastes and even illness. By following this straightforward cleaning routine, you’ll keep your fresh water tank in excellent condition and avoid potential health risks.

At Custom-way, we recommend regular maintenance of your entire RV water system, especially if you’re frequently on the road. If you need help sanitizing your water tank or performing any other maintenance tasks, our expert team is here to assist.


Contact Custom-way for professional RV services, maintenance, and upgrades to keep your vehicle road-ready all year round! Whether you’re a full-time traveler or a weekend warrior, we’re here to help with all your RV needs.