How to Fix Your RV Water Pump Check Valve

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A person using their hose by their RV

If you wake up to see water dripping from your freshwater tank, you may fear that you have a leak and an expensive repair on your hands. However, you might have an RV water pump check valve problem instead.

Most of the time, this is an easy fix. So let’s take a closer look at how to fix your RV water pump check valve so you can keep making memories at the campsite. Let’s dive in!

Freshwater Tank Filling On Its Own? You Might Have a Bad Check Valve 

RVers are always fixing something. RVs take a beating going down the road, and their construction isn’t always the best quality.

A common problem is when the freshwater tank fills even though you haven’t put any water in it. This happens when the check valve that keeps the city water from entering your freshwater tank goes faulty.

What Does a Check Valve Do On An RV Water Pump?

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

It also prevents water from going into your freshwater tank. If the water continuously runs into the tank, it will overflow.

Where Is the Check Valve On An RV Water Pump?

Most RVs have three locations for check valves. One will be at the cold inlet to the water heater, one at the city water inlet, and one at the outlet of the water pump.

The first check valve prevents cold water from mixing with warm water. The second one keeps water from entering the freshwater tank when on city water. Finally, the third prevents backflow and water spewing from the city water inlet when operating the water pump.

What Causes an RV Water Pump Check Valve to Go Bad?

It’s common to replace an RV water pump check valve. Some RVers even carry an extra one with them. Here are a few reasons why this small device goes faulty.

Water Pump Freezes

In the winter, when temperatures dip below freezing for several hours or days, your water lines can freeze. But it’s not only the plumbing you must worry about.

You also need to protect the water pump from freezing. If the RV water pump check valve freezes, it won’t allow water from your freshwater tank to your faucets.

You might have to take a space heater outside and blow warm air on the water pump check valve to thaw it. Once it melts, it’s not uncommon to have a cracked check valve, so you’ll need to replace it.

Hard Water Build Up 

Hard water, or water with minerals in it, can be tough on your skin and your RV plumbing system. For this reason, some RVers travel with RV water softeners.

If you consistently allow hard water to enter your water lines, you’ll have buildup from the calcium, magnesium, iron, and other “hard” minerals. Your RV water pump check valve will break if buildup causes the spring to remain open.

High Water Pressure 

If you don’t use a water pressure regulator, you’re not only risking damage to your water lines but also risking damage to your RV water pump check valve. The force of high water pressure can break the check valve.

This may be an inexpensive repair compared to fixing cracked water lines. Always use a water pressure regulator to prevent unnecessary expenses.

Keep in Mind: Should you Leave your RV Water Pump on All the Time? Click the link to learn more!

Mechanical Failure 

Finally, sometimes RV water pump check valves break. There’s no particular reason. Even if you’ve correctly winterized your RV, used water softeners, and installed a water pressure regulator, the check valve can fail.

The O-ring can unseat itself, and water can freely flow through. If the freshwater tank is overfilling, you’ll know the check valve has failed.

An RV sink working properly with an rv water pump check valve

How to Fix Your RV Water Pump Check Valve

Thankfully, fixing the water pump check valve isn’t a timely or costly repair unless you have to replace the whole water pump. Let’s examine a few ways you can fix this common problem.

Reset the Pump 

You don’t have to replace the water pump or the check valve as soon as you sense a problem. If you cycle the pump and use it for a while, the check valve can correct itself.

This is the best-case scenario for fixing your water pump check valve. Usually, this happens when you don’t use the water pump for a while.

Buy an External One-Way Check Valve 

You can also buy a check valve bypass connecting your freshwater tank line to your water pump. This connector won’t allow water from the pump into the tank.

So if water from the city connection goes through your RV water pump check valve, this external connector will be a second layer of defense to prevent the water from continuing into the freshwater tank.

Keep in Mind: 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 tricky to replace only the RV water pump check valve. It requires unscrewing a few screws to remove the water pump and then taking it apart to get to the check valve.

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

SHURFLO 94-800-03 Model 4008 Repair Parts - Check Valve
  • Built from quality materials, for durability and longevity
  • Check valve

Replace the Whole Water Pump 

If water still isn’t flowing the correct way after replacing the check valve, you may have to replace the entire water pump.

There could be further damage to the pump’s inner workings beyond the check valve. If you aren’t confident in your handyman skills, you might need to call a technician for this.

Know When to Bring in a Professional

If you’ve replaced the check valve or even replaced the whole water pump and still have water pouring into your freshwater tank, it’s time to call a professional technician.

Although there are many minor repairs RVers can do on their own, you might have a more significant problem on your hands. But exhaust all possibilities before you call for help.

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

Last update on 2024-04-22 / Affiliate links / Images from Amazon Product Advertising API

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