RV Fresh Water Tank Overflows When Connected To City Water

This is a common issue. Believe it or not, it can happen often. Not to one person but to many people who own RVs. There are simple explanations for this issue and they are not hard nor expensive to fix. But it can be an annoying problem till you do get them fixed.

There are several sources for this problem. One would be a broken or malfunctioning check valve. One way to solve this problem is to unhook from city water and run your pump for a while. This can re-seat the valve and get it working again.

To learn more about this problem just continue to read our article. It is filled with the information you want to know about so you can fix this issue when it happens to you. Take a few minutes to see how this important information can help you out with a difficult problem.

Why is My City Water Filling My Fresh Water Tank?


This is not a complicated problem nor one that is hard to diagnose. There are several sources to cause this to happen. One we just mentioned could be a check valve that needs to be re-seated or replaced.

Another could be a bad regulator. When this goes bad on you, water can get into your fresh water tank and start to fill it up. Or, you need to install a back flow preventer which is a long way of saying a new valve is needed.

Another source could be the 4-way selector valve. It can break on you in the wrong position and let a lot of water flow through to your fresh water tank. The water regulator may cost $50 but it saves you a lot of headache and frustration after it is installed.

In some cases, it could be a bad water pump or the vibrations stripped the screws causing the pump to get loose. To solve this problem, you have to find the correct source and apply the right repair.

RV Fresh Water Tank Overflows When Connected To City Water

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When you see water coming out of your freshwater overflow valve, you know you have a problem. It is not the city water connection but some internal part in your RV or trailer.

The best thing to do is shut the city water off, and then start looking for that internal part that may have failed you. Start with the water pump and check the valve. If that is not the problem, then move on to the regulators, selectors, and other parts that are connected to your fresh water tank.

You can let the dealer or closest approved mechanic work on it for you if you are under warranty. But that may cost you a day or so just for the fix. It is a decision you would have to make.

Fresh Water Tank Filling By Itself


This is not some ghost playing game son you. There is a reasonable explanation for this problem and we have mentioned about all of them to you. There is one more part to mention.

Someone could have left the quick fill valve open. If they did that then your fresh water tank will fill up on its own. Or that valve simply wore out and failed on you. It does happen.

Your tank will fill up even when the quick fill valve is in the off position. When that happens, it means a quick trip to your local hardware or RV parts outlet to get a new one.

Replacement of this part is the only option for you. It is the only option in many sources for this problem. If you are still under warranty, it is best to let the dealer handle the repair so you are not in any trouble.

How Do I Stop My Fresh Water Tank From Filling Up?

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When you notice that your fresh water tank’s overflow valve is letting water out, the first step is to shut off the incoming city water. There is no sense in wasting any more water than you already have.

The second step will be to start investigating to see what caused the problem. Once you find the failed part, then you need to go to the store and buy a new one. This is the only way to stop your tank from filling up.

The repairs should not take too long if you are not under warranty. Also, they should be easy enough that you can do it yourself if you are mechanically inclined. If you are not, then a good handyman will be able to get the repair done quickly enough.

Why Is My RV Water Pump Pumping Water Out City Connection?


The best place to look will be at the connection at the input connection with city water. There you will find a little valve that controls the direction of the water. If it is stuck open, all you have to do is move that valve with your fingertip and it should stop the flow of water to your water pump.

This little valve is called a back flow valve and if your pump is on while you are inspecting it, you should see some drops of water come out. If it is in backward, you will see a nice stream of water flowing out of the input connection.

Some Final Words

Although this type of problem looks a bit mystical but in reality it is a very real and simple problem to fix. Just take your time and make sure you have found the right part that went bad on you and replace it.

Sometimes, all you need to do is start the pump and try to re-seat that check valve. Other times all you will need is your fingertip to get the backflow valve back into its right spot. It is not rocket science but it will save you on your water usage.

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