How to Fix Your RV Water Pump Check Valve

When you wake up and see water dripping from your fresh water tank, you may worry that you have a leak and are due for an expensive repair. However, you may instead have a problem with your RV’s water pump check valve.

In most cases, the problem is easy to fix. So let’s take a closer look at how to fix your RV water pump check valve so you can continue to reminisce at the campground. Let’s dive in!

Fresh water tank filling up on its own? You may have a defective check valve

Motorhome owners are constantly fixing things. Motorhomes take a lot of abuse on the road, and their construction is not always of the best quality.

A common problem is that the fresh water tank fills up even though you didn’t put any water in it. This happens when the check valve that prevents city water from entering the fresh water tank is defective.

What does a check valve do on an RV water pump?

The check valve is located behind the city water connection. It allows city water to enter your RV’s plumbing system when you connect it to a water source.

It also prevents water from flowing into the fresh water tank. If the water constantly flows into the tank, it will overflow.

Where is the check valve on an RV water pump located?

In most RVs, there are three locations for check valves. One is located on the cold water inlet to the water heater, one is located on the city water inlet, and one is located on the outlet of the water pump.

The first check valve prevents cold water from mixing with hot water. The second check valve prevents water from entering the fresh water tank if you are using city water. Finally, the third prevents water from backflowing and spraying out of the city water inlet when the water pump is operating.

What is the cause of a faulty check valve in a mobile home pump?

It is common to replace the check valve in an RV water pump. Some RV owners even carry an extra valve. Here are a few reasons why this small device is defective.

Water pump freezes

In the winter, when temperatures drop below freezing for several hours or days, your water pipes can freeze. But it’s not just the water pipes you need to worry about.

You also need to protect the water pump from freezing. If the check valve of the water pump in the motorhome freezes, no water can get from the fresh water tank to the taps.

You may need to put a space heater outside and blow warm air on the water pump check valve to thaw it. Once it melts, it is not uncommon for the check valve to crack and need to be replaced.

Hard water deposit

Hard or mineral-rich water can be a strain on the skin and plumbing in an RV. For this reason, some motorhome owners travel with RV water softeners.

If you are constantly running hard water into your plumbing, deposits of calcium, magnesium, iron and other “hard” minerals will build up. Your RV’s water pump check valve can break if the spring is left open by sediment.

High water pressure

If you do not use a water pressure regulator, you risk not only damaging your water lines, but also damaging the check valve on your RV water pump. The force of high water pressure can destroy the check valve.

This can be an inexpensive repair compared to repairing cracked water lines. Always use a water pressure regulator to avoid unnecessary costs.

Remember: Should you leave your RV’s water pump on all the time? Click on the link to learn more!

Mechanical failure

Sometimes the check valves on water pumps in RVs break. There is no particular reason for this. Even if you have properly winterized your RV, used water softeners, and installed a water pressure regulator, the check valve can fail.

The O-ring can come loose and water can flow freely. If the fresh water tank is overfilled, you know the check valve is defective.

How to repair the check valve of the water pump in the motorhome

Fortunately, repairing the water pump check valve is not a time-consuming or costly affair, unless you need to replace the entire water pump. Let’s take a look at a few ways you can fix this common problem.

Reset the pump

You do not need to replace the water pump or check valve immediately if you find a problem. If you start the pump and use it for a while, the check valve may repair itself.

This is the best scenario for repairing your water pump’s check valve. Usually this happens when you don’t use the water pump for a while.

Buy external one way check valve

You can also purchase a check valve that connects your fresh water tank line to your water pump. This connection prevents water from the pump from entering the tank.

So if water from the city connection runs through the check valve on your RV’s water pump, this external connector is a second layer of defense that prevents the water from continuing into the fresh water tank.

Please note: Is it safe to drive an RV with a full water tank? Let’s find out!

Replace the check valve only

It’s not too complicated to replace just the RV water pump check valve. You need to loosen some screws to remove the water pump, and then you need to disassemble it to get to the check valve.

You can buy a replacement valve on Amazon or at a camping store for less than $20. For example, this SHURFLO 94-800-03 model 4008 is about $14 on Amazon.

Replace the entire water pump

If the water still does not flow in the correct direction after replacing the check valve, you may need to replace the entire water pump.

Beyond the check valve, there could be other damage to the inner workings of the pump. If you are not confident in your craftsmanship, you may need to call in a technician.

Know when to call in a technician

If you’ve replaced the check valve or even the entire water pump and water is still flowing into the fresh water tank, it’s time to call a professional.

Although there are many minor repairs RV owners can do themselves, you might have a bigger problem. However, exhaust all options before asking for help.

Have you ever had to replace the check valve on your RV water pump?

Leave a Comment

Your email address will not be published. Required fields are marked *