RV Water Pump Not Pumping Water? Do This!

To get the water from the water tank to any of the faucets, the water pump in your RV needs to be running properly and pumping water.

But what do you do if your pump is running but still not pumping water? and what causes this problem?

If your RV pump is not pumping water then it’s likely due to there being no water in your freshwater tank, your pump has sucked in air, you have a broken water pipe or there is an electrical or mechanical problem with your water pump motor.

Keep reading for a detailed explanation of each cause, and most importantly what you need to do to fix your RV water pump.

Why Your RV Water Pump Is Not Pumping Water + Fixes

RV water pump not working

1. There’s No Water In The Tank

One of the most common causes is simply because there is no water in the freshwater tank. It sounds quite silly, but this is something that does happen fairly often. 

Maybe you used too much water the day before, or maybe you forgot to fill the tank up in the first place. Whatever the case might be, the pump obviously cannot pump water if there is no water to be pumped. 

The easiest way to try to see if there is water in the water tank is to take a look at the sensors or the water gauge. The inside of that water tank should have a sensor, which then provides you with information via the water gauge.

You should be able to see this on the water tank itself, although in some modern RV models, you may be able to check this on the display on the dash. 

Another thing that you can do is to try to fill up the water tank and listen to see if there is water coming from the overflow. If there is water coming from the overflow, it means that the tank is full. 

You can also go old school and give the tank a good knock with your fist. If it sounds hollow and empty, then there’s probably no water inside of it. Of course, if this is the problem, the solution is to fill up the tank.

Related: What happens if you leave your water pump on.

2. The Pump Sucked In Air

If the pump has sucked in air due to the way in which gravity works then it won’t be able to suck in any water.

If you open up your faucets and they continuously sputter and have more air coming out of them than they do water, this may very well be the cause. What you should try doing here is to see if there is water in the line or pipe that connects the freshwater tank to the pump.

Open up the pipe a little bit to see if water comes out. If there is water coming out, then there is water flowing from the tank to the water pump, in which case this is not the cause.

However, if you open up the pipe and see that there is no water, or very little water, in between the freshwater tank and the water pump, then it is likely that that pump has sucked in air.

Once the pump has sucked in air, it won’t be able to suck in water again unless you fix the issue. To fix this issue, you need to manually fill water into the pump itself. 

In other words, you have to manually prime the pump and get that water suction started. Once you have filled the pump with water, turn it on manually, and it should create enough suction to once again start sucking in water.

3. A Broken Pipe

Yet another common cause is some kind of break in one of the pipes or tubes. It could also be that there is a split, worn, or loose connection that is leaking water. So, check to see if you can see any water leaking out anywhere.

If there is a leak in one of the pipes that leads from the water pump to one of your faucets, then you will see very limited water coming out of your faucets when you go to turn them on.

This is of course because most of the water is leaking out of the pipe somewhere between the pump and the faucets. If there is a leak in the pipe that connects the freshwater tank to the water pump, then you will likely not have any water coming out of your faucets at all.

This then goes back to the fact that the pump is going to be sucking in air through that crack, which will then affect its overall section.

Therefore, what you need to do is to check all of the pipes to see if they are damaged or have cracks in them. If the pipes have damaged or cracks, then you will need to fix them using the appropriate methods.

There are some pretty easy ways to remove damaged sections of pipe and then replace them with new sections. If the damage is severe, you may just need to replace the pipe as a whole. 

On a side note: if there are leaking or damaged pipes, you should see evidence of this. There should be a pool of water somewhere under your RV, or maybe at the base of it somewhere by the water tank. If you have a huge puddle of water somewhere, you can rest assured that this is the issue.

Next, if it is one of the fittings or connections that is loose, then all you have to do is tighten them. If the connections are tight, then they may be damaged, in which case you should see a leak at the connection points. Of course, the solution here is to fix or replace any connection points that are damaged or leaking.

4. Electrical or Mechanical Issues with the Pump OR the Power Supply

If the water tank is full, the pump hasn’t sucked in air, and there are no broken or leaking pipes, then the only other issue that could possibly be the cause is some kind of electrical or mechanical problem with the motor.

Now, there can be a variety of issues that can occur with these water pump motors. While all of the other issues on the list today are things that you could probably deal with yourself, electrical issues with the pump are slightly more difficult.

If you have absolutely no knowledge of water pumps or electrical systems and wiring, then you will likely need a professional to help you with this. However, if none of the other three issues are the cause, this is probably it.

It may be that a part of the water pump is stuck, that the belt operating the pump is broken, that the diaphragm of the pump is ruptured or punctured, or that the impeller is worn out.

If the pump is stuck, it could mean that there is a damaged component on the inside that can no longer move, in which case that component will need to be replaced. 

If the diaphragm is punctured or ruptured, then it will have to be replaced. If the impeller is worn out, this will also have to be replaced. It may also be the case that the impeller has debris in it, in which case you may be able to clean it out. 

That said, if you have no knowledge of electrical systems or water pumps, then diagnosing exactly which of these electrical or mechanical issues is the cause is going to be difficult.

In all honesty, if the pump motor is broken, chances are pretty big that you will need to buy a new pump altogether. As is often the case, some of these components cannot be easily replaced, and if they can, whether or not the cost is worth it is questionable.

On a side note, if the pump doesn’t turn on or make any sound at all, it could be that there is some kind of issue with the wiring or the power supply. Therefore, go check the breaker box to see that breaker has not been tripped, or if you are still using old school fuses, that fuse is not blown. 

You then also want to make sure that all of the wiring that supplies that water pump with power is intact and in good condition. If you have ripped, torn, or damaged wiring, this will need to be replaced.

Other Common RV Water Pump Issues

There are also some other common issues that occasionally happen with RV water pumps, so let’s take a quick look at those;

  • You may find that your water pump is cycling on and off periodically. This can be caused by a leak in the piping or a leak in the water pump.
  • You may find that your RV water pump makes a whole lot of noise, which is most likely caused by loose or weak connections. Just make sure that everything is tight.
  • If the pump is making a lot of noise, it could also be that one of the interior components is damaged or loose, such as the impeller, which will cause it to rattle and scrape against the housing.
  • If your water pump does not work after having been winterized and stored for the winter, check to see if all of the shutoff valves are open, and if the drain is open.
  • If your water pump is leaking a lot of water, check to see if there is any kind of break or crack in the pump itself.
Madeline Cooper