Keeping Your Water Fresh, Clean, and Safe: How To Sanitize an RV Tank

Having access to water is an amenity that some RVers may take for granted until they notice that the water in their RV has a foul odor, tastes strange, or becomes unsafe to drink or use.

The key to keeping your RV water clean, fresh, and safe is by sanitizing your RV tank. Here’s what you need to know about sanitizing your tank as well as the steps to take to ensure it’s done correctly.

The Benefits of Sanitizing Your Tank and How Often You Should Sanitize

Before you sanitize your RV water tank, you might be wondering if sanitizing is a necessity (especially if you don’t drink the water) and how frequently you should sanitize the water tank. It doesn’t matter how often you use the water in your RV or even how you use it; it’s best to sanitize your water tank at least every six months.

If you suspect there’s an issue with the quality of your water, or if the water you have in your tank was under a boil advisory due to contaminants, you may need to sanitize your tank sooner.

Sanitizing your water tank is the best way to ensure that your water tastes good and is safe to consume or use. Failure to sanitize your water tank can lead to bacteria growth and other issues that may cause bigger (more expensive problems) down the road.

Supplies, Cost, and Time Needed to Sanitize Your RV Water Tank

Before we give you step-by-step instruction on how to sanitize your RV water tank, here’s the list of supplies you need. The prices listed are starting or average prices, but you may find the prices vary depending on where you purchase them (online or at a store).

  • One external water filter: $10
  • One internal water filter: $20 (you may have more than one internal filter)
  • Bleach (varies on size and brand): starts around $2 for a gallon
  • A funnel with a flexible hose and stopper (this is often found at an auto part store starting around $3)
  • A water filter wrench for your internal filter: $5 and may be included with the filter

Other useful supplies include a container for mixing bleach and water, measuring cups, and rags for wiping up any spills.

Don’t sanitize your water tank until you have at least 12 hours to complete the process. Sanitizing may take as little as five hours or up to around 12 hours.

Additional Tips to Consider Before You Start

You should never sanitize your water tank with water that is not clean or unsafe for consumption. If you have a water heater, flush it out before you sanitize your water tank. Fellow RVers can offer helpful advice, cautiously use any advice that is vastly different from our instructions below.

Follow These Steps to Sanitize Your RV Water Tank

Ready to sanitize your RV water tank? Follow these steps:

Step 1: Make sure you have everything you need before you get started. This will make the process go more smoothly and quickly.

Step 2: Sanitize your funnel and hose with bleach, allowing it to sit for about 15 minutes.

Step 3: Drain about one-quarter or half of your water tank. If the water is not safe to use, drain the whole tank and find clean water and refill half-way or three-quarters. Never pour full-strength bleach directly into the tank.

Step 4: Prepare your water and bleach mixture before sanitizing the tank. A good rule to follow is for a 40-gallon water tank, mix one cup of bleach with 4 gallons of fresh water. Never “double up” on bleach.

Step 5: Using your funnel and hose, pour the mixture into the fresh water fill.

Step 6: Add fresh water to the tank until it comes out of the overflow hose.

Step 7: Turn on the water pump, so you use water from the tank.

Step 8: Run the chlorinated water through all water lines for about two minutes. It’s normal to smell chlorinated water.

Step 9: Turn on your fresh water supply and top off the tank with fresh water.

Step 10: Let the water in the tank sit for at least four or five hours to ensure the tank is sanitized. Some RVers wait overnight.

Step 11: After the sanitation period is over, drain the water tank until it’s empty and fill with fresh water.

Step 12: Turn off the fresh water supply, turn on the pump, and begin flushing the water lines. You should do this until the smell of bleach is gone.

Step 13: If the smell of chlorinated water is still present after a few minutes of flushing, drain the tank again, refill, and start the flushing process again.

Step 14: Turn off your water supply and remove the external filter and replace it with a new one. Do the same with your internal water filter.

Step 15: The final step is to refill your water heater if you have one (follow the manufacturer’s manual as each RV heater is a bit different).

One more tip to consider: Whether you’re browsing new RV prices or looking for a used RV on an RV Finder, it’s important to make sure that the water tank is in good condition and that you understand how to fill and empty it before purchasing an RV.