RV Water Pump – A Complete Guide! Install, troubleshooting, reviews, FAQs

RV Owners

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 complete guide for your RV water pump. Whether you’re wondering how to prime an RV water pump, what causes RV water pump leaks (and how to fix them), what to do when you’re experiencing problems with your water pump after your RV’s long winter(ized) nap, what you need to know about 12 volt pumps or which water pump is best. We have all the answers and detailed information here for you, so let’s get started!

Table of Contents:

Intro to RV Water Pump

Why 12-Volt Water Pumps

Best 12V Water Pumps

Troubleshooting

How to Replace RV Water Pump

FAQs

 

Repairs on Plumbing System

Meet the RV Water Pump

The average RV comes with a 50-gallon to 200-gallon fresh water tank.  This water is your lifeline when traveling, or when camping without hookups.  Your ability, to consume the water in your tanks, comes via the little wonder known as: the RV water pump.

Here are a water pump’s two main jobs:

Job #1 The first job of the RV water pump is to provide pressured water from your rig tank.  RVs store their water in built-in tanks, which are usually located in the base of the motorhome or trailer. Your unit has three types of tanks.  The fresh water, gray (or used) water, and black (or waste) water tank.  A pump allows you to get water from the kitchen and bathroom faucets, and keeps the shower and toilet flowing.  Most RV water pumps are small and run off your RV battery.  (Generally, that means water pumps are 12 volts).

Job #2 The second job, of the RV water pump, is to provide a certain amount of water per minute.  Trailers or campers may use pumps that produce 3.5 gallons of water per minute.  Larger motorhomes may use pumps that provide 5.3 or greater gallons per minute.  Gallons of water per minute equate to pressure per square inch, or psi.  When your rig is connected to city water, it will often bypass the RV water pump, because city water is already pressurized.

Thankfully, most RVs come with their own built-in pump. But if, for whatever reason, you’re looking to buy a new water pump, the most common type of pump you’ll see for RVs is the 12V water pump, no matter the type or brand.

12V Water Pump: what you need to know + why it is important 

12V water pump RV models are the standard operating motors for RV use. These are not to be confused with a 110V water pump or 120V RV water pump, as these models are generally made for other purposes, generally in residential homes. The differentiation is key as the plumbing system in your RV is not the same as your home, so no matter what you purchase the one requirement not to forget is 12-Volts! 

There are three main metrics in relation to your water pump you can to be aware of.

  • Gallons per minute, or GPM, is the rate of water flow as measured in how many gallons of water a pump can process per minute. Pumps on the weaker end may have GPM ratings of 1.2 or so, while pumps with GPM ratings of more than 4 are considered “high volume” water pumps.
  • Pounds per square inch, or PSI, is another measure, this time of pressure rather than flow. RV plumbing systems are built to handle pressures between 40 and 60 PSI, so you’ll want to be sure to avoid any pumps that advertise higher pressure ratings than that range.
  • Amperage, or amps, is a metric you’re probably already familiar with. It measures the amount of electricity a water pump needs to draw in order to work. While most RV water pumps draw very little electricity, high-volume pumps can draw up to 15 amps of power.

Different Types of 12-Volt RV Water Pumps

Along with different manufacturers, brand names, and specs there are also different types of 12V RV water pumps. The main three are:

  • Constant speed
  • Variable speed
  • High volume

The most common of these are constant speed pumps, which, as their name suggests, deliver water at one speed only. Basically, these pumps are either off or on, and that’s it. Variable speed pumps, on the other hand, can create water pressures similar to what you’re used to in your home. Their in-built pressure sensor adjusts the speed of the pump motor to ensure the water is delivered at a constant pressure. They tend to be quieter — but also more expensive — than their constant-speed counterparts.

Finally, high volume water pumps are designed to deliver water at a higher rate of flow than the standard 12V water pumps found on board most RVs. They also require more electricity to operate, and so they’re usually found only on larger, 50-amp rigs. A pump is considered “high volume” if it’s got a flow rate of more than four gallons per minute, or GPM.

What is the best 12V RV water pump?

You’ll want to decide a few things before you start shopping. Think about whether your priorities are to pump as much water as possible, or to have an extremely quiet pump, or if you just want something that pumps water at the cheapest available price. Once you know what’s important to you in a water pump, you can begin to narrow down your choices.

There are a few major RV water pump brands.  Aquatec, Shurflo, Aquajet, SeaFlo and Flojet are the top three.  The key is finding a simple, easy to install pump, that features a quiet motor.  Aquatec boasts two units which are both quiet and offer basic installation.  Remember, an RV water pump will make noise, especially if you have multiple faucets open at one time.  This is not unusual.  Look for a pump with a 5-chamber design.  They offer greater water and pressure flow, along with a smooth overall action.  A good RV water pump will produce an even flow of water.  A jerky flow indicates variable speeds, with not enough pressure.

Well-reviewed water pumps

  1. The Flojet Quiet Quad II RV 12v water pump gets good marks for being quiet, delivering 1-3.2 gallons of water per minute at up to 35 PSI, and delivering a smooth flow of water
  2. Reviewers also like the Shurflo 4008 Revolution water pump because it runs quietly, has thermal protection technology and a built-in check valve to guard against overheating and high pressure, and it can run dry for a while without getting damaged.
  3. The Aquajet Variable Speed RV water pump delivers a 3.5 gpm flow rate, reduced power consumption to be compatible with existing electrical systems, and easy installation. Reviewers also say this is a good, quiet pump.
  4. The SeaFlo High Pressure Marine Water pump can pump up to 5 GPM, giving you a nice powerful shower like you’d enjoy at home. They’re about $100 on Amazon.

So what should you look for when you plan to buy a new RV water pump?

  1.  Check your RV manual for water specifications.  If you don’t have the manual, you may want to call a dealer or service center that is proficient in your particular brand of RV.
  2. How many gallons of water per minute is optimal for your recreational vehicle?
  3. What water pressure is recommended for your type of recreation vehicle?
  4. What are the dimensions of your current water pump?

Now test to see what your current water pump is producing.  You can check your gallons per minute by placing a 1-gallon milk jug under the faucet.  Open the faucet, and clock how long it takes to fill.  Divide that into a minute and you will have your actual operational gallons per minute.  The next step is to test your water pressure.  Purchase a water pressure test gauge, online or from your local dealer.  This gadget will allow you to test water pressure in your unit, as well as water coming into your tanks via the campground.

Before purchasing a new RV water pump, consider these few things. First, check to make sure your existing pump can’t be fixed – you can find a great guide to troubleshooting water pumps coming up next. Then, think about your water pump priorities – lots of pressure, quiet operation, inexpensive price, or other features. Pick the most important to you and start by looking at pumps at the top of the list in those areas. With a little research, you’re bound to find one you’re happy with!

man doing repairs with electric drill

RV Water System Troubleshooting

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. Let’s go over some common issues and easy DIY fixes. 

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 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. 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!

4. 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.

5. 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.

6. 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.

table with plumbing materials for repairs

How To Replace your RV Water Pump

First, you’ll want to shut off your water supply and ensure the RV is disconnected from any electricity. You don’t want to get electrocuted over this DIY upgrade! Be sure also to turn off the breakers at the inverter, so your RV battery doesn’t keep a live current running through the wires.

Locate your RV’s 12V water pump, and use the appropriate tools necessary — most likely a screw driver — to loosen the hose clamps and pull the hoses off the pump. Then, remove the fixtures holding the pump itself, and take that out as well. Cut the old wires connected to your pump, remembering which lines up with which end of the appliance. Then, drop the new pump into place and replace the wires, hoses, and fixtures. Voila! A new water pump.

In summary:

  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.
  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!
  3. Disconnect the water lines to and from the pump. (Expect to get wet and prepare with towels!)
  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. Follow the instructions included with your 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 kind of important!)

If the above steps sound a little out of your league, that’s no problem! You can easily find an RV repair service who will be willing to help you replace your RV water pump. The trick is finding one that won’t charge you an arm and a leg for the service!

Fortunately, we’ve whipped up this piece on finding trustworthy and affordable RV repair help that won’t cost you an arm and a leg for basic services.

Don’t forget to test your new install before walking away from your project! Having a bucket and some towels handy in case of a loose connection, test your water pump by turning everything back on. 

FAQ RV Water Pump

How do I prime my 12V RV water pump?

You may need to prime your RV water pump after replacing it, or if your RV’s been out of use in storage for a time. Fortunately, priming an RV water pump is easy!

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.)

 And finally, rest assured that many modern RV water pumps are self-priming, meaning you won’t have to worry about any of these steps!

How long do 12V RV water pumps last?

When well cared for, an RV water pump can last up to 10 years — though, of course, there’s always some variation depending on manufacturer, model, and plain old luck of the draw.

Is there a difference between 12v RV water pumps?

Yes, actually, there is. While all those pumps operate on the same voltage, they can vary in power and pressure. The best way to see a water pump’s power is to see how many gallons it can pump in a minute. You can also check the PSI, but gallons pumped per minute is pretty easy to understand. Look for one that pumps at least three gallons per minute for decent power. A Flojet RV water pump is a good brand that’s easy to find and pumps a good amount of water through quickly.

Where can I learn more on how to do RV repairs with confidence?

If you want to become a professional yourself, NRVTA has courses that will help you save time and money by teaching you to maintain and repair the majority of RV issues on your own. Click here and use code RVSHARE for 5% off all courses.

The RV Owners home study course comes in two options. 

Online & USB

  • The USB version is $297 and includes booklets, a tweaker screwdriver, and a USB Drive with all of the HD videos. It also includes a copy of the online version. This is perfect for RVers who may not have access to good wifi or likes to have a physical copy. 
  • The Online version is $197 and includes all of the same videos laid out in chapters using our online portal. It’s good for RV owners who have good wifi, don’t want to wait on UPS, or like to keep everything digital. 

& that’s a wrap!

We hope you found this complete guide useful and it covered all your questions! Did we forget something? Ask below!

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