Water pump cycles on and off

Jason.rhodes86 · 06-17-2022, 04:03 AM

Our water pump cycles on and off constantly when not being used. This started the last time we used it, but after a shower it stopped and I thought maybe worked itself out. Set up yesterday and worked fine for hours then started doing it again. I’ve checked best I can and have not discovered any leaks anywhere. Any ideas? I tried to attach a video but it won’t work. Basically it’ll run for 2-3 seconds then stop for 3-5 then run then stop until I turn it off.

**chuckster57** · 06-17-2022, 04:07 AM

First thing is make sure all the air is purged. You need to open every faucet valve and run it for about 15 seconds, this includes the outside shower if you have one. If that doesn’t work, then you may have water pump issues.

**JRTJH** · 06-17-2022, 04:28 AM

Additionally, don't forget to check the low point drains to be sure the caps are on tight/valves completely off, check the water heater pressure relief valve, the anode threads in addition to purging all the air out of the system.

If none of these are found, then it's time to start looking for a loose fitting, split hose, leaking city water connection inlet valve. If none of those are found, possibly freeze damage from winter storage, so lots of "belly work".. But, before starting that, I'd look at the water pump to make sure it's working properly. Many (maybe even most) water pump cycling issues are caused by trash or plastic drill shards being drawn into the pump diaphragm from the fresh water storage tank. Those things wind up in the FW tank during construction of the trailer and without a strainer on the water pump inlet, they create havoc for the water pump.

skids · 06-17-2022, 04:59 AM

Flush the FW tank's low point drain with plenty of water. If you have a FloJet pump, get an inlet filter. If running water with all the valves open as suggested above doesn't dislodge the bits of junk, you may need to take the pump apart. It is fairly easy.

Jason.rhodes86 · 06-17-2022, 05:25 AM

I will try all of the above. How do you flush the low point drain?

skids · 06-17-2022, 05:46 AM

Quote:

Originally Posted by Jason.rhodes86

I will try all of the above. How do you flush the low point drain?

Really I should have said to flush the FW tank out of the low point drain. Just open the white petcock and drain water. You may want to and more into the fill port a few times to chase out all of the offending bits.

Jason.rhodes86 · 06-17-2022, 06:29 AM

Quote:

Originally Posted by skids

Really I should have said to flush the FW tank out of the low point drain. Just open the white petcock and drain water. You may want to and more into the fill port a few times to chase out all of the offending bits.

Ok so you’re saying just open the low point drain to let some water flow thru

bsmith0404 · 06-17-2022, 05:38 AM

Low point drains just need to be closed, not flushed. If there’s any small leak that allows pressure to escape it’ll cycle to pump, including the low point drains. It doesn’t take much. To give you an idea, I was sanitizing my system the other day, I just finger tightened the anode rod, I knew it would leak. There was a very small, snow leak coming from it and my pump did the exact same thing. I finally got the sockets out and tightened it because it also wanted to make sure the system pressurized properly and I don’t have any leaks. In my case, all was good. The point is, any small leak will do exactly what you’re describing. Hopefully it’s something simple and purging the lines will fix your problem.

**flybouy** · 06-17-2022, 06:42 AM

If it's construction debris the best thing you can do after clearing the pump is to add a strainer on the intake line of the pump. Simply flushing out the FW tank may not be effective. Have you ever pulled the stopper to drain a sink after washing dishes and have to wipe stuff off the bottom of the sink basin?

RV holding tanks are typically shallow and very flat. Getting floating objects to flow down a drain requires a fast flowing high volume drain. A lot of folks report that adding a strainer can capture debris for some time, even years. IMO it's easier to clean out a strainer a couple of times vs tearing apart the pump several times.

JBM3M · 06-17-2022, 08:33 AM

I find if I go from tank water to city water I get air in system on change. FYI

rabreen · 06-23-2022, 07:24 AM

Quote:

Originally Posted by JBM3M

I find if I go from tank water to city water I get air in system on change. FYI

Likewise. If I've forgotten to switch from "Fill" to "Normal" in the wet bay and I'll get the cycling of the water pump.

Jason.rhodes86 · 06-17-2022, 09:19 AM

Well I ran all the faucets and then opened the low drain valves purged them and still no luck. That’s about I can try here so I’ll have to dig more into it when get home I guess. Just strange it worked fine for first few hours now this. Thanks for the help.

dutchmensport · 06-17-2022, 09:29 AM

Just a though.... are you attached to city water and do you have the city water / shore water faucet turned on AND your water pump turned on? Or are you completely disconnected from shore water. When I am on shore water (which is very, very seldom) and I don't turn my water pump off, mine acts very similar.

But more than that, I almost always forget to flip the valve from "Fill" to the "Normal Run" position after filling my tanks. The pump will cycle for a second about ever 20 minutes when I forget to flip the valve. And if I flip the wrong valve and flip the winterizing valve, the pump runs constantly as it's trying to suck air. I have my "Oh Duh!" moments too ... far too often!

Jason.rhodes86 · 06-17-2022, 09:32 AM

Quote:

Originally Posted by dutchmensport

Just a though.... are you attached to city water and do you have the city water / shore water faucet turned on AND your water pump turned on? Or are you completely disconnected from shore water. When I am on shore water (which is very, very seldom) and I don't turn my water pump off, mine acts very similar.

Not in city water. Filled the tank on arrival

Pathfinder75 · 06-23-2022, 09:33 AM

Quote:

Originally Posted by Jason.rhodes86

Not in city water. Filled the tank on arrival

WHEN Tank FILL VALVE is in the fill position your pump will cycle.on. MUST MOVE VALVE OFF of Fill when not filling tank

bobnelms · 06-23-2022, 04:23 PM

A quick follow-up... why do you typically use the water pump versus shore water???

Hoodlatch · 06-26-2022, 12:33 AM

Quote:

Originally Posted by bobnelms

A quick follow-up... why do you typically use the water pump versus shore water???

I’ll answer this real quick. Many people camp in areas where there isn’t shore water…. State parks, national parks, and the great BLM and other properties. My current camper is now 8 years old and has had full hookups 2 times. Everyone has a preference.

TO THE OP, did you find the problem? If it’s not air(commonly missed is outside shower like mentioned above), check your pump! Mine was “leaking” at the center seal. It had very little water under the pump that was hard to see. I caught it by seeing a couple beads of sweat building up where the two halves of the pump are held together. A little muscle with a screwdriver on the four screws solved my issue. I had roughly the same cycling as you, a couple seconds on every few minutes.
I hope you found issue, get out there and use it.

Jason.rhodes86 · 06-26-2022, 07:51 AM

Quote:

Originally Posted by Hoodlatch

I’ll answer this real quick. Many people camp in areas where there isn’t shore water…. State parks, national parks, and the great BLM and other properties. My current camper is now 8 years old and has had full hookups 2 times. Everyone has a preference.

TO THE OP, did you find the problem? If it’s not air(commonly missed is outside shower like mentioned above), check your pump! Mine was “leaking” at the center seal. It had very little water under the pump that was hard to see. I caught it by seeing a couple beads of sweat building up where the two halves of the pump are held together. A little muscle with a screwdriver on the four screws solved my issue. I had roughly the same cycling as you, a couple seconds on every few minutes.
I hope you found issue, get out there and use it.

I use the water pump because I’m not usually at full hookup site, electric only. So I fill my tank on arrival.

I have not figured out the issue. The thing that makes me think it’s not a leak is because it’ll randomly stop cycling at times for a while. A leak would not fix itself for a couple hours then start leaking again. I have opened all faucets to include outside shower isn’t helped. So I’m likely gonn have to look into the pump itself.

**JRTJH** · 06-26-2022, 09:05 AM

Quote:

Originally Posted by Jason.rhodes86

I use the water pump because I’m not usually at full hookup site, electric only. So I fill my tank on arrival.

I have not figured out the issue. The thing that makes me think it’s not a leak is because it’ll randomly stop cycling at times for a while. A leak would not fix itself for a couple hours then start leaking again. I have opened all faucets to include outside shower isn’t helped. So I’m likely gonn have to look into the pump itself.

One "non plumbing issue" that you might consider is the electrical connections/battery condition. The pump motor MUST spin at the required RPM to drive the pump diaphragm fast enough to deliver pressure sufficient to activate the pump pressure switch. If the voltage/amperage is just barely at the minimum (caused by corrosion on the connections, loose electrical connections or a bad/discharged battery, etc) the pump may not be able to achieve the pressure adequate to go beyond the "bare minumum"....

I've seen several "run on pumps" that will run under nominal pressure load at full speed, then, as the water pressure builds, the pump doesn't have enough amperage to continue at full speed and the pump starts to "wind down" until it's barely "burping to attain water pressure"... The pressure switch will close, but as that "trace of air in the low point drain or elsewhere" allows the pressure to drop slightly, the pump will "burp again"... Sometimes it will keep doing this on a continual basis.

You might want to check all the electrical connections to the pump, feel the wires, the twist on connectors or the caps on the swedge connectors to see if they're warmer than they should be.

If there's no "plumbing reason for the pump action" it may be an electrical issue.....

dutchmensport · 06-26-2022, 04:33 PM

Quote:

Originally Posted by bobnelms

A quick follow-up... why do you typically use the water pump versus shore water???

I'll answer too. We do not run water from shore water. We always fill the fresh water tank and pump from there. We've been doing this for over 20 years, 3 travel trailers, and now our Fifth Wheel. Why?

First? And the most important reason, water pressure. when using the on-board water pump, we never have to worry about over pressure, a pressure regulator, or anything like that. We always have consistent water pressure and no threat of over pressure, breaking pipes, or pipe joints.

Second? We did (a long time ago), keep the garden hose hooked up, until one very hot summer day, the garden hose actually exploded.

Third? I have never had a garden hose, (white, green, blue, or black) that did not leak at the connections. Leading water at the connections is such a waste of water. Its one thing having a little leak when filling a tank, or a bucket. But to leave the leave running 24x7 for a several days while hooked up, is just a horrible waste of everything.

Forth? No danger of tripping over garden hoses laying on the ground, campground workers mowing over one, or theft, or even "kids play" when kids (might) mess with your stuff .... being kids, or just being a little on the rotten side! (Kids are kids... and even some adults are just plain cruel).

Fifth? When pumping water from the fresh water tank, we keep track of our water usage, and also helps determine how much water is in the black and gray tanks. Water in, water out, knowing how much you use, and how much you waste is being a responsible camper.

Sixth? If we ever do have a water leak, the water pump will start cycling on and off and we can hear that. If the water pump kicks on and we are not running water ... it gets our attention real, real fast. Sometimes it's a faucet drip, or it might be the water heater drain plug, or even the pressure relief valve on the water heater. But when we hear the pump cycle ... we jump to action immediately! If hooked up to city water, you could easily run 100 gallons of water and flood the underbelly of your camper and never know it.

For all these reasons, we pump from our tank.

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