How to Drain RV Fresh Water Tank

How to Drain RV Fresh Water Tank : Simple 9 Step Guide

When freshwater sits in an RV tank for an extended period, it may lead to many problems, including unsafe drinkable water and water-borne diseases. To avoid any health hazards, you must have some understanding of how to drain RV fresh water tank.

For RV owners, the most significant thing you need to do before traveling with one is drain the tank. Once you have finished using your RV for the season, you must drain the RV fresh-water tank. This prevents damage caused by ice expansion when the ground freezes in winter.

The process of draining an RV’s tank can be challenging at first glance if you do not know what to expect or how to proceed. Just 30 gallons of water in your RV’s water tank can add 250 pounds of extra weight. Let’s discuss how to drain RV freshwater from the holding tank without wasting time. 

What are RV Holding Tanks?

What are RV Holding Tanks

The RV holding tank is what allows you to store water in your RV. These holding tanks are typically located below the flooring or along the walls of an RV. Holding tanks are relatively small, so it won’t take long before they reach capacity.

In general, there are three types of holding tanks in an RV, such as: 

  1. Fresh-Water Tank: The fresh-water tank is where you store freshwater, which is used for potable water, cooking, and cleaning.
  2. Gray Water Tank: Gray tank holds used water from bathtubs, showers, and sinks, not contaminated by toilet waste. Two gray tanks may be found in large travel trailers and fifth wheels.
  3. Black Water Tank: Black water holding tank is used to hold water from your toilet, containing waste. If your RV does not have a gray tank, all dirty water is dispensed into these black tanks.

Tools for Draining Fresh Water Holding Tank

Tools for Draining Fresh Water Holding Tank

There are certain tools that you must need to properly fresh-water tank drain from your RV’s, such as:

  • Water Hose
  • Water Pressure Regulator
  • Potable Water Hose Adapter
  • A spigot wrench
  • Drain Pan / Bucket
  • Rags/ Paper towels

How to drain RV fresh water tank – Step By Step Process.

To properly fresh-water tank drain from your RV, you will need to follow the following steps:

Step 01. Park Your RV in a Safe Place:

Your first step is to park your RV in a safe place, such as a flat area or an open garage. You need easy access to both the water hose and sewer hose to the fresh-water tank drain.

Step 02. Turn Off The Water Supply:

Once you have parked your RV in the exact location, go ahead and turn off the water supply to your RV. You can do this by closing the main water valve on your RV, usually located near the fresh-water tank. This step will also prevent any leaks when you disconnect the drinking water hose later on.

Step 03. Disconnect The Water Supply:

Now that you have turned off the water supply to your RV disconnect the water supply hose from your water tank. Simply grip the connector with your hand and give it a quarter turn to disconnect it. A firm tug will help remove any remaining water in the line.

Step 04. Open All Faucets to Drain Standing Water:

Open all faucets in your recreational vehicle to allow the standing water inside them to drain out. You can then close each tap after an adequate amount of time has passed.

Step 05. Connect The Water Hose to The Tank:

Next, connect your water hose to the tank’s outlet valve. Ensure that the end of your water hose is compatible with the valve’s opening. You can also use a water pressure regulator to protect your RV’s fresh-water tank from the excessive force that may occur during fresh-water tank drain.

Step 06. Turn on The Outlet Valve:

Turn your RV fresh water tank’s outlet valve to the open position. The water will start draining out of your freshwater tank immediately. You can use a hose bib to drain water from tanks faster to speed up the process.

Step 07. Check The Water Level:

Check the water level in your fresh-water tank periodically to ensure it does not go below the point where the outlet valve is attached.

Step 08. Disconnect Water Hose When Water Flow Stops:

Once the water flow stops, go ahead and disconnect your water hose from the outlet valve. Remember that you should never turn on your fresh-water tank without attaching it to an RV freshwater supply first.

Step 09. Turn on Fresh Water Supply & Refill Tank:

You are now ready to reuse your RV’s fresh-water tank whenever you need it. To do so, simply turn the water supply back on and refill the clean water tank until it reaches capacity.

Why It’s Important to Know How to Drain Fresh Water?

Why It's Important To Know How to Drain Fresh Water

Knowing how to drain RV water tanks properly will save you a lot of time and energy. Having the right tools and knowledge on doing it properly will ensure that there isn’t any wasted water.

Otherwise, you may have to deal with a very wet and smelly situation, which is not an ideal outcome for anyone. By knowing this simple process, you can avoid the need to call a professional every time something goes wrong with your RV’s clean water tank.

Tips for Properly Drain Fresh Water System

Some helpful tips for adequately draining your fresh-water tank are:

  • Use a Water Pressure Regulator.
  • Make sure to use a compatible water drain hose.
  • Keep your fresh-water drain valve open when draining the portable tank to avoid getting clogged up.
  • Try hooking up two sewer hoses for the faster drain.
  • Keep your fresh-water tank’s level above the drain plug at all times.
  • Make sure that you use a bucket or pan to catch any leaks during the draining process.
  • Letting food particles get into the gray water tank will add to the odors you smell if you haven’t drained the gray water tank.

Why Should You Always Clean Your Tank Before and After Use?

It’s essential to clean your RV’s fresh-water tank before and after each use to prevent any build-up of bacteria or algae. Not only will this make your tanks last longer, but it will also keep your water tasting clean and fresh.

You should also be aware that leaving water in your water tank for an extended period is not only bad for the water tank but can also lead to mold growth. Mold is not only gross to look at, but it can also cause illness when ingested.

Safety Precautions When Cleaning and Draining Tanks?

Safety Precautions When Cleaning And Draining Tanks

When cleaning and draining your RV’s fresh-water tank, it’s essential to take a few safety precautions to prevent any accidents from happening. Here are a few things to keep in mind:

  • Turn OFF the freshwater supply to your RV before cleaning the water tank.
  • Turn off any anti-siphon drain valves if you have one installed on your RV’s clean cold water lines.
  • Always wear gloves and safety goggles when working with detergents or other chemicals that may harm your skin or eyes.
  • Do not use any chemicals to help speed up the draining process because they can damage your clean water tank if not used properly.
  • Ensure that all drain valves and drain hose connections are closed securely before using your RV’s fresh-water system again.
  • If your freshwater tank has an anti-siphon valve, make sure it is closed before using the water tank again.
  • Always keep a bucket or pan underneath any potential leak points during the cleaning and drain process.
  • Lastly, always turn the water on first and then attach your drain hose when refilling your RV’s fresh-water tank.


Here are some frequently asked questions about RVs that people are most interested in: 

01. Where Can I Drain My Rv Water Tank?

It should be the best filtration tank in any city. The EPA (Environment Protection Agency) has no official rule for where you should drain your water. Because the water isn’t full of bacteria, you can drain it anywhere. You can legally drain your RV fresh-water system into either a household sink, toilet, or storm sewer.

02. What is an RV Septic System?

An RV disposal system does the same to your gray and black water tanks. It separates the solid waste from the water to be disposed of in a more environmentally friendly manner.

03. How Do I Maintain My RV Sewage System?

How Do I Maintain My RV Sewage System

The simple answer is to flush it out properly. You have to clean your black water tank at least once a month, especially if you use the RV more frequently. Follow the manufacturer’s guidelines for properly disposing of other waste.

04. Do I Need a Special Hose for My Freshwater Tank?

Your tank should be filled with fresh, potable water from a reputable source using a dedicated water drain hose. For draining, you don’t need a special drain hose for your RV fresh-water tank. Any standard garden hose will do the trick.

05. How Often Should You Clean Your Tanks?

You should always clean your black and gray water tanks before you start to use them in your RV. For freshwater, this is only necessary if you are using the RV a lot.

06. What is The Best Time of Day to Drain Your Tank?

It’s best to drain your water in the morning when the temperature is cool. This is because the water will cool down at night, leaving less room for bacteria or algae growth.

07. When can I Refill My Fresh Water Tanks Again After Draining It?

You can refill your tank whenever you want. Ensure that the water is clean and free of debris or sediment before filling your water tanks.

08. How Long can Freshwater Stay in RV Tanks?

You can keep the water tank empty for up to 14 days, as long as you have a water supply on the site. If the weather is hot, it’s essential to keep your tank filled with fresh water.

09. How Often Should You Sanitize RV Freshwater Tanks?

It is recommended that you sanitize your water tank at least every six months or more frequently if you are in an area where the water is not cleaned regularly.

10. How Long Can Black Water Stay in The RV Tank?

RV black water tanks are designed with enough excess capacity to break down human waste naturally. You can store it in your tank for up to ten days, but make sure you use the RV regularly during this time.

11. How Often Should I Empty My Tanks?

This depends on how often you are using your RV. If you are staying in one place for longer than two weeks, then it is recommended that you empty the tanks every 3-5 days during this time.

12. How to Locate the Fresh Water Drain Valve?

To locate the fresh-water drain plug, you need to open your water fill. Generally, the drain for your fresh-water tank is located under the underbelly of your RV, directly under your freshwater tank.

Final Words

Even if you are an experienced RV owner, there is always more to learn. It’s important to know the proper ways of maintaining your tanks. Any standing water or residual matter in this tank must be removed not to contaminate the new supply of clean water when drained into them.

Remembering these simple steps on how to drain RV fresh water tank will help ensure that your stay is as enjoyable and relaxing as possible.

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