An RV water pump is a vital piece of equipment in any recreational vehicle. Its purpose is to draw water from a freshwater tank and deliver it to the various fixtures and appliances inside the RV that require water.
One of the most common problems that RVers face is that their water pumps keep running even when there is no demand for water. This can be extremely frustrating, as it not only wastes water but also runs down the battery and puts unnecessary wear and tear on the pump itself. There are a few different reasons why this might happen, so let’s take a look at some of the most common ones.
What could be causing the water pump to run constantly in your RV?
If you’re troubleshooting your RV water pump and trying to figure out why it’s running constantly, these are some of the most likely culprits. Let’s take a look at each one in more detail so you can narrow down the problem and get your water pump back to working properly again.

The pressure switch is not working properly
The pressure switch is a vital part of the RV water pump system. Its job is to turn the pump on and off according to the water pressure in the system. If the pressure switch is not working properly, it can cause the pump to run constantly, even when there is no demand for water.
There are a few different things that can go wrong with the pressure switch, so it’s important to troubleshoot it carefully. First, you’ll want to check that the switch itself is not defective. You can do this by testing it with a multimeter. If the switch is defective, it will need to be replaced.
Another possibility is that the pressure switch is not adjusted correctly. The pressure switch needs to be properly calibrated in order to work correctly. If it’s not, it can cause the pump to turn on and off at the wrong times, which can lead to the pump running constantly.
If you’re not sure how to adjust the pressure switch, you can consult the owner’s manual for your RV or contact a qualified RV technician.
There is a leak in the system somewhere
If there is a leak in the water system, it can cause the water pump to run constantly in an effort to keep up with the demand. Water leaks are one of the most common causes of this problem.
There are a few different places where leaks can occur in an RV water system. The most common places are at the fittings and connections. Over time, these can become loose and allow water to leak out. Another possibility is that the hose itself is damaged and leaking.
If you suspect that there is a leak in the system, the best way to confirm it is to check the fresh water tank. If the level in the tank is dropping even though you’re not using any water, then you know there’s a leak somewhere.
Once you’ve confirmed that there is a leak, you’ll need to repair it before the water pump will work properly again. This will usually involve replacing a faulty fitting or connection, or repairing or replacing a damaged hose.

The check valve is faulty
The check valve is a one-way valve that prevents water from flowing back into the fresh water tank. It’s located between the tank and the water pump. If the check valve is not working properly, it can cause the water pump to run constantly.
There are a few different things that can go wrong with the check valve. The most common problem is that it becomes stuck in the open position, which allows water to flow back into the tank. This can happen if there is debris or sediment in the valve, or if it’s simply worn out.
Another possibility is that the check valve is installed incorrectly. If it’s installed backwards, it will allow water to flow back into the tank even when it’s supposed to be closed.
If you suspect that the check valve is the problem, you can remove it and inspect it. If it’s damaged or installed incorrectly, you’ll need to replace it.
The demand for water is too high
In some cases, the constant running of the water pump may be due to a high demand for water. This is most likely to occur if you have multiple people using water at the same time or if you’re using a lot of water for something like showering.
If this is the case, there’s not much you can do about it other than wait for the demand to go down. Once the demand for water has decreased, the pump should stop running constantly.
However, if the high demand for water is due to a leak, you’ll need to find and repair the leak before the pump will work properly again.
The water pump is defective

In some cases, the problem may be with the water pump itself. This is most likely to occur if the pump is very old or has been used extensively.
If the water pump is defective, it will need to be replaced. This is a job that should be done by a qualified RV technician.
The water pump is too small
Another possible reason for the water pump to run constantly is that it’s too small for your RV. If the pump can’t keep up with the demand for water, it will run constantly in an effort to meet that demand.
If you think that the water pump is too small for your RV, you can consult the owner’s manual or contact a qualified RV technician. They will be able to recommend the correct size pump for your RV.
The water filter is dirty
If your RV has a water filter, it may be causing the water pump to run constantly. A dirty water filter can restrict the flow of water, which can lead to the pump working harder than it needs to.
If you think that the water filter is the problem, you can remove it and inspect it. If it’s dirty, you’ll need to clean or replace it.
The water lines are frozen
If your RV is in a cold climate, the water lines may be frozen. This can restrict the flow of water and cause the pump to work harder than it needs to.
If you think that the water lines are frozen, you can try thawing them out with a space heater or hair dryer. You can also pour hot water on them, but be careful not to scald yourself.
There’s something wrong with the electrical system
In some cases, the constant running of the water pump may be due to a problem with the RV’s electrical system. This is most likely to occur if the RV is old or has been used extensively.
If you think that the electrical system is the problem, you should consult a qualified RV technician. They will be able to diagnose and repair the problem.
Citations
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/24163695/print/true.cfm
https://www.irv2.com/forums/f278/water-pump-keeps-running-461776.html
https://www.rvforum.net/threads/new-water-pump-constantly-runs.105711/
Ever since I was a kid, I've been fascinated by travel. I inherited this passion from my parents. Since my college years and to this day, I have had a passion for traveling in a motorhome. I am here to share my experiences with you.