RV Water Pump Runs But No Water – What To Do?

Your RV's water pump is a critical feature that must be kept in good condition. It provides water for drinking, bathing, washing dishes, and toileting. RV water pumps usually have long lives with few problems, but occasionally you may encounter an issue. For example, if you hear the pump running but no water is coming from the faucets, what should you do? We've done the research, and we have the answers for you!  

If your RV water pump is running, but you're not getting any water, follow these troubleshooting steps: 

• Check the water level in the freshwater tank. 
• Examine the freshwater tank for leaks. 
• Check the main freshwater line for leaks, loose connections, kinks, and clogs.
• Ensure that the water filter is not clogged.
• Make sure the pump is primed.
• Check that the pump is functioning properly.
• Examine all water lines and ensure that all valves are open.

In the remainder of this article, we'll provide a detailed description of each troubleshooting task. We'll also answer the most common questions RVers have about the functioning of their water pumps. Keep reading to learn more! 

Troubleshooting: Pump Running But No Water

Check The Water Level In The Freshwater Tank

The first step in troubleshooting is to ensure there's enough water in the freshwater holding tank. This may seem simplistic, but it's easy to overlook. If there is no water in your holding tank, you'll get nothing but air from your faucets. If the water level is low, you will get a mixture of air and water. 

First, check your freshwater tank gauge to see how much water is in the tank. If the gauge shows an adequate water level, but the water is still not running, the gauge or sensors may be malfunctioning. So, before you do anything else, double-check the water level by inserting a clean wooden dowel into the tank until the end of the dowel contacts the bottom of the tank. Then withdraw the dowel and measure how high the waterline is to determine whether there's sufficient water in the tank. 

If your water tank gauge or sensors are malfunctioning, you may need to replace them.

Click here for a water tank gauge on Amazon. 

Examine The Fresh Water Tank For Leaks

If your freshwater holding tank is empty, but you're sure you haven't used that much water, check the tank for leaks. The simplest way to do this is to follow these steps:

1. Flush the freshwater tank several times.
2. Refill the tank with freshwater.
3. Park your RV on a paved surface (where leaks will be easily visible).
4. If you are able, crawl under the RV and inspect the holding tank for leaks or cracks.
5. Leave the RV parked for several hours, then move it and inspect the ground for wetness.

If you find a minor leak in the tank, you may be able to patch it. You can purchase a repair kit, like the one shown below, and seal the leak with the enclosed epoxy. If the leak is major, you will need to replace the freshwater holding tank.

 

Click here for a plastic tank repair kit on Amazon.

Check The Main Water Line For Leaks, Loose Connections, Kinks, And Clogs 

If you've determined that your freshwater holding tank is full and has no leaks, but you're still not getting water, the next step is to check the main water line for leaks, kinks, clogs, and loose connections. If this line is not functioning properly, it will not conduct water to your faucets. 

This is a tricky process because the line may not be entirely accessible for viewing. Depending on where it is located, you may have to roll under the RV to view the freshwater holding tank's connection.

• Examine any part of the main fresh water supply line you can see for cracks, bulges, kinks, or leaks.
• Inspect the connectors for leaks; tighten any loose connectors.
• Examine the RV's interior near where the main supply line branches off to service the toilet, sinks, and shower. Look for evidence of leaks in nearby cabinets and on the floor. 
• If you discover a crack or a clog in the supply line, replace the line.
• You should be able to straighten out a kink in the supply line manually.
• If a connector continues to leak, even after you tighten it, replace the connector. 

 

Click here for an exterior RV water line on Amazon.

Ensure That The Water Filter Is Not Clogged

If you have installed a water filter in your RV's freshwater system, check to ensure that it is not clogged. The simplest way to do this is simply to remove the current disposable water filter and replace it with a new one. If you have recently put a new filter in and think it's unlikely that a clogged filter is the problem, you may want to hold off on trying this until you have completed all of the following troubleshooting tasks.

Click here for this Camco water filter on Amazon.

Make Sure The Pump Is Primed

If the previous tasks don't identify your problems, the next step is to examine your pump to ensure it is working correctly. The simplest issue with your pump may be that it needs to be primed. If your RV is older, it probably has a rubber priming bulb attached to the pump: squeeze the bulb multiple times to inject water into the pump. In newer-model RVs, priming the pump is even easier: you simply open all the cold water faucets and then turn on the pump. The change in pressure will bring water from the holding tank, through the pump, and then out through the faucets.

Check That The Pump Is Functioning Properly

If priming the pump doesn't fix the issue, you may have a problem inside the pump itself. First, determine whether there is water flowing from the holding tank to the pump:

1. Make sure the pump is turned off.
2. Carefully disconnect the supply-side water line from the pump.
3. If the line has water in it, it is functioning properly: re-connect it to the pump.
4. If the line is dry: check it again for cracks, kinks, and clogs. Repair or replace it if needed.
5. After repairing/replacing a dry line, fill it with water again and re-connect it to the pump.
6. Turn the pump back on, open the faucets, and see whether water begins flowing again.

If the problem is not in the supply line, determine whether water is flowing out of the pump:

1. Make sure the pump is turned off.   
2. Disconnect the outflowing water line from the pressure side of the pump.
3. Turn the pump back on. Have a bucket handy for this step, in case the water starts spewing out.
4. If water just drips or trickles out of the pump, you will probably need to replace the pump.
5. If water flows normally out of the pump, then you know your pump is working properly.

Click here for this Shurflo RV water pump on Amazon.

Examine All Water Lines And Ensure That All Valves Are Open

If you have completed the preceding troubleshooting tasks, to know that your water tank, main supply line, and pump are all functioning, your next step is to check the freshwater supply lines leading to the sinks, shower, and toilet. 

1. Leaving the pump on, shut off all the water valves.
2. Inspect each water line for cracks, bulges, and kinks.
3. Examine each connector to make sure it is tight and not leaking.
4. Check each valve to make sure it is tightly connected.
5. One at a time, turn each faucet on and open the valve that services it.
6. If water does not flow out of a faucet, re-check its water line, connectors, and valve; repair or replace malfunctioning parts as necessary.  

If you have completed all the troubleshooting tasks above and your pump continues to run without pumping water, there is likely a leak somewhere that you can't detect or a problem within the pump that is impossible to see without disassembling the pump. In that case, it's time to take your RV to a professional repair shop. Remember, if at any time during the troubleshooting process you get frustrated or decide you'd rather be enjoying your vacation than tinkering with your RV's water system, you can always let a professional do the investigation and repair!

Can You Leave Your RV Water Pump On?

RV water pumps are designed as on-demand pumps -- they only turn on when you open a faucet or flush the toilet. So, if you leave your RV's water pump switch in the "ON" position, the pump will not continue to move water or draw power from your battery system, except when you actively use the water. 

The only exception to this rule occurs when you are hooked up to a municipal water system for your water supply. In this case, if you turn your RV's pump "OFF," the municipal system bypasses the pump and provides the water you use for washing up, showering, and toileting. If, on the other hand, you leave your pump switch "ON," the pump will continue to use water from your freshwater holding tank whenever you open a faucet or flush the toilet.  

How Do You Reset Your Water Pump?

RV water pumps do not have reset buttons. If your pump abruptly stops working, follow these troubleshooting steps:

1. Let the unit sit for 15 to 20 minutes and see if it restarts on its own. Some models have an automatic shutoff that de-activates the pump when the unit is too hot.
2. Check the fuse visually to make sure it hasn't blown.
3. Even if the fuse looks good to your naked eye, test it with a voltage meter, just to be sure.   

If none of the preceding steps solves the problem, ensure that your RV's battery system is functioning properly:

• Check your owner's manual to determine whether your RV has a battery disconnect switch; if so, make sure that the switch has not been inadvertently shut off. 
• Check all the breakers and fuses in your RV's electrical box. Make sure they are all turned "ON."
• Examine the connections on your house batteries; make sure all are clean and tight.
• Check the electrolyte levels in your batteries, and add water to any that are low.
• Make sure the batteries are fully charged.
• Check that the battery voltage is around 14.4 with the engine on, using the generator, and hooked up to electricity.

If none of these troubleshooting steps work to get your water pump running again, consult a professional RV repair person.

How Long Does An RV Water Pump Last?

When properly cared for, an RV water pump can last 10 years or more. Make sure you never run your pump when the freshwater holding tank is empty. Protect the water system from freezing; if your RV is sitting dormant in a cold region, make sure you winterize it before the cold weather arrives. And protect your pump from corrosion and mineral deposit buildup by adding clean, relatively mineral-free water to your freshwater holding tank.  

Should You Travel With Water Tanks Full Or Empty?

Full water tanks increase your RV weight, so many owners wonder whether traveling with the tanks empty will improve gas mileage. A full 40-gallon tank, with water weighing eight pounds per gallon, adds 320 pounds to the total weight of your RV or travel trailer. Depending on the rig's overall weight, the extra pounds in a water tank can increase your gas expenses by 1% to 5%. On the other hand, knowing that you won't have to scrounge around for fresh water at the end of a day of travel may make the extra expense worthwhile to you.  

How Long Can A Pump Run Dry?

The answer to this question depends on the construction of your pump. Older RV water pumps are designed with an impeller, a small plastic piece critical to moving water through the pump and pressurizing the flow. If left "ON," these pumps will overheat and break down within a few hours to a day. Most newer, high-quality pumps use a diaphragm and chambers, rather than an impeller, to move water. These pumps are designed to be able to run dry for days at a time without damage. 

In Closing

Keeping your RV's pump and water system functioning efficiently is one of the most important challenges for an RVer. If your pump runs but no water comes out of your faucets, you can complete troubleshooting tasks to determine what is wrong. The solution may be as simple as filling your water tank or replacing a piece of water line or as complex and expensive as replacing the entire pump mechanism. Keep the system working well, and you'll enjoy onboard water for all your travels!

You may also find the following posts informative:

RV Water Pump Won’t Turn On – What To Do?

RV Water Leak? Here’s What to Do