How to Drain an RV Fresh Water Tank Step-by-Step

Draining your RV fresh water tank is a relatively simple process. But there are some crucial steps to take to do it correctly, which we outline below.

Before we begin, you’ll first need to locate your fresh water tank drain valve and the low point drain valves (if you don’t know where they are already). They are typically located underneath your RV below or near the freshwater holding tank, but this will vary.

If you can’t find your drain valve, check your RV’s owner’s manual for the location. See below for links to the owner’s manuals for a few of the most popular RV and 5th wheel manufacturers.

How to Dump a Fresh Water Tank & Lines Step-by-Step

1. Turn off the hot water heater before you drain the fresh water system.
2. Wait for water in both the fresh water system and the heater holding tank to cool down to room temperature.
3. Open all of the faucets, including the outside shower, if you have one.
4. If applicable, set the RV water heater to the bypass position to prevent water from entering the heater tank.
5. Open the fresh water tank dump valve and let the water drain out. 
6. Open the low-point drain plug or valve. There should be one for both the hot and cold water lines.
7. Flush the toilet until water stops flowing.
8. Turn the fresh water pump on as needed, removing any remaining water from the freshwater lines.
9. Remove the water heater drain plug and allow the water to completely run out. Check out our guide on how to drain an RV water heater for some important tips!

Important: These are general instructions for draining your fresh water system. Please consult your owner’s manual for instructions specific to your camper model.

Where Is the Fresh Water Tank Drain?

Typically, the fresh water tank drain location is located on the underbelly of your RV, right underneath your freshwater tank, and will be attached to a pipe or hose. However, this will vary by manufacturer and model.

You should check your RV’s owner’s manual for the exact location of your drain valve. If you can’t find your owner’s manual, you may have to reach out to the manufacturer to get a copy. Below are links to the owner manuals for a few of the most popular RV manufacturers:

• Jayco Owner Manuals
• Forest River Owner Manuals
• Grand Design Owner Manuals
• Keystone Owner Manuals
• Winnebago Owner Manuals
• Thor Owner Manuals
• Airstream Owner Manuals

Tip: The information to drain your fresh water tank is usually in the plumbing system section of the manual.

Should I Leave Water in My RV Fresh Water Tank?

If you plan on winterizing or storing your RV for an extended period of time, you should drain your fresh water tank.

Tip: Generally speaking, you should only keep fresh water in your RV tank for about two weeks. However, many factors can affect how long your potable water will remain fresh. Check out our in-depth guide on how long to keep fresh water in your RV tank for some important information and best practices.

Why? Eventually, the water in your freshwater tank will become contaminated and unhealthy to cook with or drink.

Even when traveling, it’s wise to drain both the fresh water tank and the waste tanks beforehand (or keep the tanks nearly empty). Traveling with full tanks will add weight to your motorhome, causing wear and tear and increasing fuel consumption.

You can always fill the RV water tank with fresh water when you reach your destination.