RV Water Pump Guide: Installing, Troubleshooting, FAQs and More 

When your RV water pump is not working, you won’t 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 dealing with an RV water pump not working or wanting to replace your unit entirely, we have all the answers and detailed information here for you.

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RV Water Pump Troubleshooting

When it comes to RV water pump problems, many of them are fixable, even if you’re not a mechanical expert. Let’s go over some common issues for your RV water pump not working. 

Pump Runs, No Water Flow

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.

1. First, make sure that there is actually water in your freshwater tank. This may seem obvious, but it’s an easy thing to forget. Check the tank gauge. If your tank is empty or low, your RV water pump will not work. (It needs something to pump!)
2. Now that you know there is water in the tank, 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. If the water line seems dry, then the issue is the water line coming to the pump from the tank.
3. In the case of a dry water line, check to see if there is any type of blockage or tube damage. Then 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. Have someone watch for the outpour. Anything?
4. If there’s 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. 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 reset button at your cue.) Disconnect the water line from the pressure side of the pump.
5. 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 the water only trickles out, then you most likely need a new water pump. If the water coming out seems to be pressurized, then the issue is between the RV water pump and the actual RV faucets.
6. Shut off all the water valves and start checking the water lines to the faucets. Look for cracked lines, loose connections, and clogs. If you find clogs, broken water lines, or loose connections, try fixing these issues. This should solve your problem. If not, it might be time to call in a professional.

Pump Won’t Turn on After Winterization

A pump that won’t turn on after winterization 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 whether 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 section, then you may need to fully replace the RV water pump.

Pump Cycling On and Off

You’re sitting there enjoying a nice, quiet evening when 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. It will need to be replaced. If you’ve thoroughly inspected your RV water system and haven’t found the leak, then you know what to do: seek a qualified RV repair professional!

Quieting a Noisy Water Pump

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. 

Try the following:

1. Locate the water pump and turn it off. It may be under the bed, under the sink, or under the rig.
2. Turn off the pump.
3. Remove the pump by unscrewing it and putting a piece of felt or rubber padding under the pump. Now screw the water pump back on. TADAH! No noise from constant travel vibrations!
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.
5. Pumps that turn on and off in rapid succession create 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’re 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.

How to Prime an RV Water Pump

Realizing you need to prime your RV water pump and have no idea how to go about it? Good news! This is a really common issue, and it’s really no big deal to fix. Here’s how to prime an RV water pump. 

1. Fill up your fresh water tank.
2. Turn on the cold water in your RV and make sure the faucets are completely open.
3. Switch on the water pump near your RV water tank.
4. This should prime the pump by pushing water up from the tank through your faucet. Let the water flow awhile 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!)
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.

Shopping for an RV Water Pump

Is it time for a new 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, to have an extremely quiet pump, to pull as little electricity as possible, 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.

Different Types of 12-Volt RV Water Pumps

Along with different manufacturers, brand names, and specifications, 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. These, 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 pressure 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, so they’re usually found only on larger, 50-amp rigs. A pump is considered “high volume” if it has a flow rate of more than four gallons per minute (GPM).

What to Look for in an RV Water Pump

Now that you know what type of RV water pump might be good for you, you’ll need to consider what might fit well in your RV. 

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?
5. How many amps can your electrical system handle? Most RV water pumps don’t draw much average, but some draw as much as 15 amps. 

Well-Reviewed Water Pumps

There are a few major RV water pump brands, including Aquatec, Shurflo, Aquajet, SeaFlo, and Flojet. The key is finding a simple, easy-to-install pump that features a quiet motor and fits within your budget. 

Here are some of our top picks.

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 water pump – especially the 4008 Revolution, because it runs quietly, has thermal protection technology and a built-in check valve to guard against overheating and high pressure, and 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 quiet pump.
4. The SeaFlo High Pressure Marine Water pump can pump up to 5 GPM, giving you a powerful shower like you’d enjoy at home. They’re about $100 on Amazon.

RV Water Pump Replacement

Now that you know how to find and buy the perfect replacement RV water pump, it’s time to install it. 

1. First, you’ll want to get rid of all water in your fresh tank and shut off your water supply.
2. Next, ensure the RV is disconnected from any electricity. Be sure to also turn off the breakers at the inverter, so your RV battery doesn’t keep a live current running through the wires.
3. Locate your RV’s 12V water pump, and use the appropriate tools necessary — most likely a screwdriver — to loosen the hose clamps and pull the hoses off the pump. 
4. Remove the fixtures holding the pump, and take that out as well. 
5. Cut the old wires connected to your pump, remembering which lines up with which end of the appliance. 
6. Remove the old pump, drop the new pump into place, and replace the wires, hoses, and fixtures. Making sure to use teflon tape and line the water pump up correctly. 
7. 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, and test your water pump by turning everything back on. 

If the above steps sound a little out of your league, that’s no problem! You can look for an RV repair service willing to help you replace your RV water pump. 

Hopefully this guide has helped you know what to do when dealing with an RV water pump not working, so you can continue to use and enjoy your RV’s water system. Now that your pump is fixed, where will your next adventure take you?