Water Pump Sometimes Runs when not calling for Water

[Mark Ulmer]

Hi, everyone. Last week, I was camping with my Rockwood MiniLite 2109S in a state park that had no water hookup. So, I filled my freshwater tank and turned on the water pump. Everything worked fine. However, just occasionally (maybe once or twice a day), I would hear the water pump running even though I wasn't asking for any water. When this happened, it would only run for a second or so and then shut off right away. I checked for dripping faucets, but they were all securely closed. I also checked as best I could for leaks in any water lines, but couldn't find any. Any idea why this happens?

[bikendan]

Most common cause is a water or air leak somewhere.

[propbndr]

Check valve may be leaking by when the pump is off.

[Lefty59]

We've experienced the same thing. I've noticed it seems to normally occur when the temperature changes from nighttime to daytime or the hot afternoon cools into evening. I've just assumed it is a pressure variance in the pex piping caused by the temperature variations. I think it also could be caused by expansion or contraction in the contents of the water heater tank.

Either way, I haven't seen any signs of leakage so I've not been too concerned as it is a fairly infrequent occurrence.

Happy camping!

[BooBoo23]

I don't very often need to use the water pump (winterizing is about the only time), but I don't leave it turned on. I turn it on when I have a demand then turn it back off. My system doesn't leak down so I don't have the occasional on/off of the pump. It may be a leaking check valve on the pump since you can't find any drips anywhere.

[kg4gfv]

Sounds like check valve to me. Just replaced mine for around $17

[fedexflyer]

if you have an ice maker in your refrigerator it may just be coming on to make ice a couple times a day. I used to turn my water on when underway only when I need it, but was always short on ice, now I leave it on while I drive and have plenty of ice.

[Mark Ulmer]

Thanks for the replies, everyone. No icemaker, fedexflyer, so that's not it. I'll take a look at the check valve.

[KAS]

Originally Posted by Mark Ulmer

Hi, everyone. Last week, I was camping with my Rockwood MiniLite 2109S in a state park that had no water hookup. So, I filled my freshwater tank and turned on the water pump. Everything worked fine. However, just occasionally (maybe once or twice a day), I would hear the water pump running even though I wasn't asking for any water. When this happened, it would only run for a second or so and then shut off right away. I checked for dripping faucets, but they were all securely closed. I also checked as best I could for leaks in any water lines, but couldn't find any. Any idea why this happens?

I have noticed the same thing, and also that the pressure INCREASES by itself. Both occurrences seem to be caused by temperature fluctuations in the water that is sitting in the pipes (shade or air conditioned vehicle vs. sun beating down on the RV). As long as there is no visible leak anywhere, this shouldn't be a problem. However I do wonder whether the excessive pressure buildup could cause a leak.

[SimchaSabre]

As already stated, it could be a very small leak anywhere in your plumbing. One more place to check is the check valve in your city water port. I've had problems before with that valve re-seating after city water usage.

Try removing the screen/washer inside the city water port and then push the valve in to release some pressure (and water). When you release the valve it will re-seat, hopefully with a better seal. At least in my case it did. If the pump now stays off, then that would be a pretty good indicator that it is time to replace your city water port.

[Wolverine 1945]

Check all faucets,,, make sure there is no air in the system !!!

[jeff64]

Originally Posted by Mark Ulmer

Hi, everyone. Last week, I was camping with my Rockwood MiniLite 2109S in a state park that had no water hookup. So, I filled my freshwater tank and turned on the water pump. Everything worked fine. However, just occasionally (maybe once or twice a day), I would hear the water pump running even though I wasn't asking for any water. When this happened, it would only run for a second or so and then shut off right away. I checked for dripping faucets, but they were all securely closed. I also checked as best I could for leaks in any water lines, but couldn't find any. Any idea why this happens?

x2 on the check valve leak.

If you looked at an exploded view of the pump, you see the inlet and outlet check valves are most often an umbrella style. Outlet check valve holds line pressure as does your city water check valve. If you see no leakage from city water fill (or its capped off)and none from your faucets, connections or terlit, that is most likely what you're looking at. Depens how annoying that seepage is to you whether you fix it or ignore it

[phillyg]

Very small leak somewhere in the system and sooner or later you will find some water dripping out. In my case some yahoo put a screw through a water line while installing an access panel at the factory. Finally discovered where when water dripped out of the front cap!

[aceinspp]

No reason to leave on all the time. Like turn it off I do. Later RJD