An RV water pump will turn on when it needs to pump water from the freshwater tank to wherever there is demand for it.
If your RV water pump keeps running even when you’re not using it, there’s a problem!
But don’t worry, fixing this common issue is easy.
So, let’s learn why the water pump in your RV may constantly run even when no water is running and go through the most common troubleshooting steps to get the problem fixed ASAP!
Why Is My RV Water Pump Running Continuously?
If your RV water pump is continuously running even when you’re not using it, there’s a pressure leak somewhere in the system. It could be as obvious as a faucet or tap left open to a leaking line or connection.
To find the exact issue, we need to run through a series of troubleshooting steps.
RV Water Pump Troubleshooting
When your RV water pump keeps cycling on and off or continuously runs, you’ll need to carefully inspect every pipe, connection, and various valves in the freshwater system to effectively troubleshoot the issue.
While RV owners of all skill levels should be able to troubleshoot this issue, remember if you don’t feel comfortable with these steps, then take your RV to a certified professional.
Important: Always disconnect the power and water to your RV pump before attempting repairs.
With that out of the way, let’s get started!
A Faucet or Tap Was Left Open
We’ll start with the most obvious step – a faucet or tap was left open, causing the water to run and the pump to cycle continuously.
Before we continue, check all of the faucets in and outside of the RV to ensure they aren’t on (including the outside shower if you have one). Carefully look for even the smallest dribble of water coming out. Sometimes they are left on without even knowing.
Dirty Water Pump Filter
Arguably, one of the most common reasons an RV water pump runs continuously is a dirty filter or screen on the pump itself.
These screens can get clogged due to dirty water from hookups at campsites, etc. And when the filters get clogged with dirt and sediment, your pump won’t be able to reach full pressure.
So, access your water pump, remove the filter, clean it, and then replace it. Here’s a quick video showing how this is done.
Tip: Every water pump is different, so refer to your pump’s owner’s manual for specific instructions to clean the filter.
Once the filter is clean, you can test your pump. If it cycles off, you’ve found your issue. If not, continue on.
Water Tank Fill Switch Left On
If your camper has the ability to switch between city fill and water tank fill, be sure to switch it back to city fill when you’re done filling up your water tank, or the pump will continue to run.
Not every camper has this option, but it’s a common reason for RV water pumps to continuously run on campers that do feature it.
There’s a Leak in the System
Next, we need to check for a water leak in your plumbing system.
Start by looking for obvious water leakage signs – water puddles or dripping in or underneath your RV or travel trailer. Carefully follow the water lines from the pump to each outlet in your RV. And don’t forget to check the toilet for any water leaks, too!
If you find a leak, you’ll need to make the necessary repairs, which could be as simple as replacing a washer to more time-consuming tasks like replacing entire sections of damaged piping.
Tip: Take your RV to a certified professional if you’re uncomfortable making the necessary repairs.
Bad Tank Fill Valve or Backflow Preventer
A bad tank fill valve or backflow preventer could leak water back into your fresh water tank, creating a drop in pressure and causing your RV water pump to continuously cycle on.
This video will help you isolate which one might be the problem.
Incorrect Voltage to Water Pump
If everything checks out so far, we’ll want to quickly measure the voltage going to the 12v pump using a voltmeter. I’ve personally never run into this issue, but Pentair (a popular water pump manufacturer) recommends this step for a pump that keeps running.
Essentially, if the meter shows the proper voltage within ±10%, you’re good to go. If not, you may need to investigate your RV’s power system for potential issues.
Bad or Incorrectly Set Pressure Switch on the Pump
Your RV water pump has a built-in pressure switch that will shut it off when it’s reached the set pressure. If the pressure switch is not functioning correctly or has been adjusted, it may cause the pump to continuously run.
In this case, you will either have to replace the switch or adjust the pressure switch setting (usually the turn of a screw).
Here’s a quick video on how to replace a pressure switch on a Shurflo 4008.
Of course, your water pump model may be different, so you may need to check your specific model’s user manual or contact the manufacturer for more information on replacing the switch or adjusting the pressure switch screw.
Tip: If you’re still experiencing issues with your RV water pump constantly running, you may need to replace the water pump or contact a certified RV technician.
And if you’re having issues getting water to come out of your faucets (even though the pump is running), check out our guide on how to prime an RV water pump with some important troubleshooting tips!