Is it Bad to Leave the Water Pump on in an RV?


If you’re just starting with the RV lifestyle, though, you might not know much about how your pump works. Essentially, it pumps water from the tank to your faucets when not connected to an external water source. But, is it bad to leave the water pump on in an RV?

Here’s what I’ve learned from my RV:

Leaving your water pump on isn’t usually bad for your RV. But it’s not necessary if you are connected to a water supply at your campground. Plus, with the pump adding pressure to the connected water supply’s pressure, it is possible to overload your system.

But that’s just a quick answer.

There’s a lot to go over with this subject, such as whether the pressure is better when connected to another water source, why it makes that pulsing sound, and why you might want to turn it off.

Let’s jump into it.

Is it okay to leave the RV water pump on?

Your water pump is okay to keep on because it’s pressure activated. Pressure activated means it only works while water is running. If you aren’t connected to an external water source, the pump is the only way to get water from your holding tank to your faucets.

But it depends on the situation. This doesn’t seem like it would be much of a problem but let’s go over why it could turn into a major problem.

If you have pets or small children, there is the possibility that they’ll turn on a faucet, and you might not notice.

If your pump is on, you run the risk of your gray or black tank overflowing, and if you don’t have a sewer connection, your campground will be flooded.

This is because once it senses pressure, it will keep going. But honestly, unless you are connected to a sewer drain at a campsite, you have this same risk with or without the water pump.

If you want to leave your water pump on whether you have hookups or not, you should get a water alarm next to your pump if you have any problems.

However, most people will tell you to simply get in the habit of turning on your pump when you need it and off when you don’t.

Let’s talk about the pump when you’re connected to city water.

Can I run my water pump while connected to city water?

You don’t need to have your water pump going when you are connected to city water because the city water system already has enough pressure.

Most of the time, you can leave your pump on because it’s pressure activated. However, the rule of thumb is to have it on when you’re using it and off when it’s not in use or you’re not in your RV.

Does this also apply when you are connected to city water?

The simple answer is no. Whenever you are connected to city water via a hose at a campground or at your house, you should not have your water pump on.

Like I mentioned before, your water pump works on pressure.

If you add pressure on top of the pressure already coming from the city water system, then you might run into a few problems. But campground water pressure is notoriously inconsistent anyway.

So for that reason, I use a pressure regulator on my water intake valve.

It prevents issues with campground water and ones from accidentally leaving the pump on while connected to fresh water.

Check out this one on Amazon that is cheap, and super simple to install. I installed mine in 30 seconds, and I just leave it connected all the time.

Your water pump is made to pump water out of your RV’s freshwater tank.

It is designed to pump this water out when you are not using hookups. Meaning this pump is used during the times you camp without hookups, such as dry camping or going on an unexpected trip.

How long can an RV water pump run without water?

Older models of RV water pumps can malfunction or break when running without water. However, most newer models are designed to go 2 or more hours of pumping without water.

So ultimately, this depends on the specific model pump you have.

As you can imagine, leaving the pump on when your freshwater tank is empty isn’t great for the pump. And it can even cause damage depending on how long you use the pump without water.

Damage usually occurs due to overheating and pressure problems; these two things tend to cause the pump to seize up.

So just make it a habit to shut off your water pump when not using it.

We all can be forgetful at times, so if you find your water pump on without water, simply do a maintenance check and remember that newer models are designed for this.

Just make sure not to make it a habit to use your pump without water. Replacement parts range anywhere from $50 to $400, not to mention if the pump breaks, you might end up with water damage costs too.

Of course, dry camping is when you are most likely going to use your water pump.

I have a recent article that talks about how long you can dry camp for in an RV. It can be useful for understanding how long your water tank will get you to avoid dry running it.

Simply click the link to read it on my site.

Why does my RV water pump pulsate?

The pulsating noise you hear with your RVs water pump on is the pressure in the pump. and pulsating noises actually indicate that your pump is working correctly. 

Normally when people hear a noise, especially when it comes from anything automotive, they assume there is a problem.

When the pressure drops because you’re using water, the pump will start and give more pressure.

When you hear the pulsating, it simply means the pressure in the pump is going from high to low, which in turn indicates that it’s doing its job.

While most RV owners find the noise annoying, there are ways to make your pump quieter. An accumulator tank will help to regulate the pressure in your RV’s water system. This will also help your pump run more smoothly.

While this noise is harmless most of the time, it’s a good idea to be familiar with why this noise can happen.

Other than basic pressure change, this noise can occur when you have a leak in your system. Usually, this can be noticed because your pump is working harder than normal.

This noise can also happen when your water tank is too low.

No water will cause your water pump to struggle. Not only will it cause this annoying sound, but as mentioned before, it can lead to needing to replace the pump completely if done regularly.

You might even have a blockage in your system. Most RV owners tend to find this problem in their filters, and it can be easily avoided with regular cleaning of your filters.

How do you get the air out of an RV water pump?

To get the air out of an RV water pump, simply turn on the faucet that is the furthest away from the water pump once the water pump is filled.

While hearing you might have air in your water pump most likely will stress you out, it’s actually easier to fix than you might think.

Just like with a car, you sometimes need to bleed the system. Bleeding a vehicle is a lot harder of a task to do than bleeding your water pump.

At this point, you’ll have water sputtering out because of inconsistent pressure.

You’ll need to run the water for a couple of minutes until you have a steady stream, as this will indicate that all the air is out of the pump. If you still have air in your pump after this, you’re going to need more tools and time.

You’ll need to hook up your RV to a pressurized source of water.

After that, you’ll need to open all water sources; this includes things like the shower and the outside faucet. Once you get that, do follow the same steps as before by letting the water circulate for a minute. After the water stops sputtering and has a steady stream, you’re all set.

Virtually all campers have water pumps. But not all RVs are created equal. 

When trying to decide what to buy, there’s a lot to consider, from price to length & weight, capacity, and more. Luckily, I even have a recent article that talks about RVs vs. Motorhomes so you can decide which is better and easier to deal with.

Just click the link to read it on my site.

Did I cover everything you want to know about RV water pumps?

RV living doesn’t have to be stressful. The last thing you should have to worry about is your water pump giving out on you.

Keep up with regular maintenance and cleaning, and you’ll have very little to worry about.

Remember that your water pump is actually very easy to fix, clean, and keep in good condition. Avoid dry running it, and never leave your pump on when you’re connected to city water.

Stay safe and happy camping.


Photo which requires attribution:

RV Living by Kathy McGraw is licensed under CC2.0

Cassandra & Jeff Campbell

Cassandra and Jeff Campbell travel on and off with their 3 daughters in a Newmar Baystar Class A Motorhome. They write extensively on both RVs, campgrounds, parenting on the road tips, remote learning & schooling, and much more!

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