Water pump cycles about every two minutes.

BogieMeister

When I  turn on my water pump it builds up pressure and then stops. Then about two minutes later it comes on again, and repeats and repeats.  When I turn off the water pump and leave it off for a period, then I turn it back on, the pump runs until it builds up pressure again and then shuts off. Then, Second verse, same as the first.

I thought it first I might have a leak somewhere, but I cannot find it. Is there a check valve in the system that is possibly leaking? If so where is it located? 

BrianZ

Have you looked under the trailer for leaks?  If none, maybe it's the pump's own check valve, in which case would allow water to flow back into the tank. 

BogieMeister

I’m leakless. If that’s a word.

Cbusguy

Air pocket?

The pump is seeing the pressure drop for some reason.   I am with Brian, for to be a leak

Sharon_is_SAM

Make sure the clear filter cap on the pump is well seated and tight.  Also, I remember a thread about adjusting the pump.  I will try to find it.

Sharon_is_SAM

Here is the thread.  RollingBnB May 2018 entries at the bottom adjusted their Shurflo pump.  Includes YouTube video.  

https://tab-rv.vanillacommunity.com/discussion/5588/pump-problems/p1

BrianZ

@BogieMeister, I don't know if this episode I had last spring is similar, but wonder if it is somehow related to what you had..

https://tabforum.nucamprv.com/#/discussion/comment/116667

Basil48192

I'm a real rookie here.  How is the pump supposed work while dry camping?  I have only had my TAB 320S for a week.  The first time I tried it, it seemed like the pump came on and stayed on as long as the water was running.  Now, it comes on for 5-10 seconds, then stops for 5-10 seconds, etc.  Any advice would be appreciated.

dragonsdofly

@Basil48192, your pump only pressurizes your water system from the fresh water tank. It is supposed to run until the system is pressurized and then it stops. It is not supposed to turn on again until you use the water, flushing or running the shower or faucet. The pump runs until the plumbing reaches the pressure shut off upper limit. The pump should not run if you are not using water. You should not be running the pump when on city water(hose hook up). While on city water use a pressure regulator, set to 50psi or below before the water enters the t@b, or you will damage the plumbing. Anything else?

Bayliss

@Basil48192, just to piggy-back off @dragonsdofly's comments, IF all your faucets are turned off (i.e., kitchen sink, shower and outdoor shower....and toilet, of course), BUT the pump is occasionally running, that may indicate that you have a leak somewhere.  As the water leaks out, the pressure would drop and the pump will kick on to re-pressurize the water line as described above.  If that is what is happening, and it is turning on and off every 5-10 seconds, then I would think that is more than a very minor leak.

As an aside, I always turn off my water pump when not using the water from the trailer's fresh water tank.  I think that is a good practice.  It is especially important to turn off the pump if you are planning on being away from your trailer (e.g., out on a hike or sight-seeing.)  I say that, because in the unlikely event that you should suddenly spring a leak in a water line, there will not be  water actively being pumped through the water lines.  

Basil48192

@Bayliss and dragonsdofly, Thank you!  But I didn't describe my situation properly.  If I am not 'running' water, the pump stays off as it should.  When I let the water run continuously, the pump cycles on and off, as long as the water is running (again, about 7 seconds on and 7 seconds off).  Previously, the pump tended to continue running as long as the water was running.  I'm guessing that maybe there was air in the system the first few time I used it, so it never came up to full pressure.  So, my question should be:  When the faucet is running, should the pump run continuously or cycle on and off?  Thanks again!

elbereth

@Basil48192, that’s normal operation.  It takes a few seconds of the water running for the pressure to drop enough to trigger the pump, which will then turn off again when it raises the pressure sufficiently.

Denny16

Yes, thus us the way it works.  If you wantbtonreducebthe cycles, you can add a small marine water accumulator tank, which will pressurize with the pump, and continue to add pressure as the tank drains, then cycle the pump.  This curs down the number of pump cycles, and reduces battery drain.
cheers

Basil48192

Thank you to all.  Opening the water valve all the way also reduces the cycling.  Thanks again!

YanniLazarus

Denny16 said:

Yes, thus us the way it works.  If you wantbtonreducebthe cycles, you can add a small marine water accumulator tank, which will pressurize with the pump, and continue to add pressure as the tank drains, then cycle the pump.  This curs down the number of pump cycles, and reduces battery drain.
cheers

Hello!  Have you done this? If so, still happy?   And model/ where?  Thanks! 

Sharon_is_SAM

@YanniLazarus - @kottum installed one in his Airstream.

Denny16

Here is one model, made by same manufacturer as the water pump: https://www.wholesalemarine.com/shurflo-pre-pressurized-accumulator-tank.html

For installation and use see: https://tab-rv.vanillacommunity.com/discussion/8131/pulsing-water-flow-fix#latest

YanniLazarus

Thank you, Denny16!