RV Water Pump Troubleshooting – What You Need To Know

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When your RV water pump is not working, you’re not going to be a happy camper — because your onboard plumbing facilities are one of the most attractive parts of RV camping.

That’s why we worked up this  go-to-guide for RV water pump troubleshooting. Whether you’re wondering how to prime an RV water pump, what causes RV water pump leaks (and how to fix them), or what to do when you’re experiencing problems with your water pump after your RV’s long winter(ized) nap, you’ve come to the right place. We’ll walk you through how to diagnose and repair basic, common water pump problems, discuss what causes an RV water pump leak.

No matter what it is that’s troubling your water pump, we’ve got the troubleshooting solution for you!

RV Water System Troubleshooting

Whether you’re new to the world of RVing or a certified professional, chances are you’ve run into some sort of RV troubleshooting issues. After all, these are big, relatively complicated machines that allow us to drive our miniature houses around the country with us!

And if you have had to deal with RV repair issues (or even simple user errors), you also probably know that hiring professional help isn’t always enjoyable. The bills from RV mechanics can quickly reach into the triple, or even quadruple digits, even for relatively minor procedures.

Which is exactly why DIY troubleshooting, maintenance and repair are great ways to save money, helping you boost your travel budget so you can enjoy more adventures in the long run. And when it comes to RV water pump problems, many of them are actually totally fixable, even if you’re not a mechanical expert. Here’s what you need to know.

1. Why does my RV water pump sound like it’s working but no water is actually flowing to any of the faucets in the trailer?

Yikes! We’ve all been there: the moment of that sinking feeling when you realize something is wrong. If your RV water pump runs but there’s no water coming out of your faucets, don’t panic.  Step back and take a deep breath. Let’s explore this issue one step at a time.

A. First, let’s make sure that there is actually water in your freshwater tank. I know this seems really obvious, but it’s an easy thing to forget.  Check the tank gauge. If your tank is empty, or even just low, your RV water pump will not work. (It needs something to pump!)

B. Now that you know your tanks are full, the next step is to check all the water lines that lead in and out of the actual water pump. Look for loose connections and worn, split or cracked lines. You want to start with the water line to the fresh water tank. Once that is done, check all the lines leading out of the holding tank and up into your rig.

C. Now you need to decide if there is water flowing to the pump. Start by carefully loosening the water line to the pump. If you disconnect it and discover water in the line you know water is traveling toward the pump, which is good news. Reconnect the line. If the water line seems dry, then the issue is the actual water line coming to the pump from the tank.

Check to see if there is any type of blockage or tube damage. Now re-establish suction by refilling the water line with water. Connect it again with the pump and turn the pump back on to see if the water begins to move toward the faucets. This could take a couple minutes to be sure the faucets are fully open and have someone watch for the outpour. Anything?

D. If there is still no water, then it’s time to break down and actually examine the pump. It’s possible that something in the motor of the pump needs to be replaced or it’s time for a whole new unit. Here’s what to do. Grab a friend and ask them to turn the water pump off and on when you need it. (That is, have them toggle the onboard RV water pump switch at your cue.) Disconnect the water line from the pressure side of the pump.

Turn the pump on and see if the water is pumping out. (It’s a good idea to have a bucket handy, in case it is!) Is it coming out quickly with pressure or does it drip, drip, drip? If only the water trickles out, then you most likely need to get a new water pump. If the water coming out seems to be pressurized, however, then the issue is between the RV water pump and the actual RV faucets.

Shut off all the water valves and start checking the water lines to all the faucets. You may be able to replace some lines and fittings on your own. Make sure the valves are tight. If you feel frustrated, don’t worry. You can always hire a professional to check the lines for you — and now that you have determined the problem you are bound to save a lot of money at the RV repair shop.

2. I winterized the RV water pump last fall.  Now it’s spring and I can’t get the thing to work.  What did I do wrong?

Ok, this happens often — and it can feel like a terrible inconvenience, right when you’re ready to take off and go on a new year’s worth of adventures. If your water pump won’t turn on after winterizing, check the following things:

  • Did you leave the drain open when you meant to be filling up the fresh water tank?
  • Did you reconnect EVERYTHING correctly after you pumped RV antifreeze through the water lines?
  • Are all the shut-off valves are currently open? (Check again!)
  • Is your pump silent? If so, have you checked to make sure there is electricity? Did you check the fuse panel?
  • Use a volt meter to check to see if you have a full 12 volts at the pump, then double check that the pump is grounded. (It won’t work if it’s not grounded.)

If you have checked all of these issues and you checked the areas mentioned in the first question, then you may need to fully replace the RV water pump.

3. What are the steps to replacing my RV water pump?

If only it was that simple! The truth is, most RVs have very little space in their undercarriage, so replacing ANYTHING can be a pain. Take a good hard look and decide whether you have the time, patience and tools to do the job right. If not, take it to an RV repair shop. It’s worth the money to have it done right the first time.

That said, if you are planning to brave the replacement process on your own, the first thing you’ll need to do is uninstall the existing, defunct pump. Here’s how to do that.

Step #1 You can’t have any water in your fresh water tank if you plan to change your pump. So make sure you drain the tank first.

Step #2 Make sure ALL of the power is off and you are not connected in any way, shape or form to the electrical connections. Seriously, check twice — this is a matter of life and death!

Step #3 Disconnect the water lines to and from the pump.  (Expect to get wet and prepare with towels!)

Step #4 Unscrew or unbolt the water pump from the RV. You may need to consult your owner’s manual for details.

Now you are ready to install your new RV water pump. There are several kinds of pumps available on the market. Many highly recommend the Shurflo 2088-554-144 Fresh Water Pump for its high pressure and gallons per minute. Follow the instructions included with the new RV water pump. It will include using some form of pipe tape or thread to tighten the water line connections. Make sure you pay attention so that you put the in with the in and the out with the out.  (Um, yep… This is kinda important!)

If your water pump met an early demise, it may be due to long term storage.  Long-term storage can increase the chance that your water pump will poop out early.

4. The pump cycles on and off with the faucets turned off. Help!

You’re sitting there enjoying a nice, quiet evening in, and you hear it: your pump cycling on and off, even though you’re not trying to run any water.

Generally, if your RV water pump keeps running even when you’re not actively using it, it indicates that you have a leak somewhere in the system. This might be due to something as simple as a loose connection or something as annoying as a crack in one of your lines or a defective RV water pump pressure switch.

Regardless, you’ll need to thoroughly inspect the entire system to try to find the cause of the leak. Loose connections or defective valves can also let air into your lines, which will lead to sputtering faucets — and sometimes, a face full of water when you’re not expecting it.

Keep in mind that if you’ve winterized your RV water system improperly, your RV water pump may have frozen — which would cause damage requiring it to be replaced entirely. If you’ve thoroughly inspected your RV water system and haven’t found the culprit of the leak, then you know what to do: seek a qualified RV repair professional!

5. Why is my RV water pump so noisy? I can hear the pipes rattle and it makes me nervous. Is there some form of RV water pump troubleshooting?

Is the noise of your RV water pump driving you batty? It could be the design or the installation. RV companies are often in a hurry to put all the parts in the right place. In some cases, this results in RV water pumps that are loose and cause vibrations that sound like banging on a pipe with a hammer. Check out the above video for an RV water pump troubleshooting, noise-fixing remedy.

Step #1:  Locate the water pump and turn it off.  It may be under the bed, under the sink or under the rig.

Step #2  Turn off the pump.

Step #3 Remove the pump by unscrewing it and put a piece of felt or rubber padding under the pump. Now screw the water pump back on. TADAH! No noise from constant travel vibrations!

Step #4 Wrap all of the water pipes with foam pipe insulation and duct tape. Make sure the insulation is at least a half inch thick. Secure it on each end. This should stop the clanging sounds.

Step #5  Pumps that turn on and off in rapid succession creates unwanted noise and additional vibrations. The easiest fix is to adjust the water pump. Check your manual and adjust the flow to low.

If you are still having trouble, it may be time to install an accumulator. Talk to a professional and be sure to tell them which RV water pump your rig currently has installed.

6. After keeping my RV in storage, I realized I need to prime the pump.  Can you tell me how to prime an RV water pump?

 Good news! This is a really common issue, and it’s really no big deal to fix. Here’s how to prime RV water pump. (Also check out the video above for extra instruction.)

Step #1 Fill up your fresh water tank.

Step #2 Turn on the cold water in your RV and make sure the faucets are completely open.

Step #3 Switch on the water pump near your RV water tank.

Step #4  This should prime the pump by pushing water up from the tank through your faucet. Let the water flow a while, then turn the faucets off. Each and every faucet needs to be purged of air, so you may want to open and close and run water to the faucets one at a time. (Don’t forget other water outlets like your showerhead and RV toilet!)

Step #5 Your pump will be fully primed when the water pump only turns on when a faucet is actually open. (Not in between.)

If your RV water pump won’t prime, refer back to the first question on this list.

7. How can I repair a leaking RV water pump?

RV water pumps should turn on every time you flush the toilet or turn on a faucet. If after you complete your tasks and turn off the water, and the pump continues to run and run, your RV water pump is likely leaking somewhere. The first thing to do is check for a broken check valve.  This valve tells the water pump when to stop.  If it’s cracked, it will often tell the pump to keep pumping which causes your fresh water tank to rise. Try this:

Step #1  With the water off, take off the current check valve. It will usually be on a tube or hose that connects the water pump to the fresh water tank.

Step #2 Place a new check valve on the line. Make sure the arrow on the valve is pointing right at the fresh water tank.

Step #3 Connect the other end of the valve to the RV water pump and make sure it’s a good fit.

Now check your RV water pump again!

If that’s not it, inspect all of the water lines in the unit. Look for cracks, splits or rot. If the lines are damaged they will depressurize the water pump and encourage it to run. You can repair a damaged water line, but the specific steps will vary depending on your RV make and model. Refer to your user handbook — and, let’s be honest, YouTube! — to find full details for your specific rig.

Conclusion

As with any RV repair, RV water pump troubleshooting is up to you. This article is intended only as a guide and a suggestion.

Although DIY RV repair and maintenance is a great way to save money in the long term, it isn’t worth it if you end up seriously bungling one of your sensitive systems. It’s always a good idea to talk to a professional before making any adjustments to your rig. Along with risking the mechanics and interior of your rig (either through faulty installation or accidental flooding), you’re also risking your life; with plumbing and electrical, fire and electrocution are real risks!

Fortunately, there are ways to find and hire trustworthy RV repair professionals, whose work is actually worth the cost they charge. Click here to learn how to find an RV repair service you won’t regret hiring!

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