No water leaks, but pump runs.

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Gordon Groff

Well-known member
Sep 27, 2006
Lancaster, PA
I have an intermittant problem with my water pump running for no good reason.  Sometimes.  When I first dewinterized a couple weeks ago, my water system held full pressure overnight with the pump off.  Cool!  The first weekend out, though, about every 15 minutes it would pump up again.  I know I have no leaks, cause that much water would be running out somewhere.  I've got an accumulator, so every pump cycle is worth a couple cups of water.  No visible water either under sinks or under the rig.  This happened once last year, but went away.  Is there some kind of check valve that keeps water from back-flowing into the fresh water tank?  Is it built into the pump?  Not a big deal, but have to turn off the pump so that stupid thing does not go BRRRRRRRR under our bed all night long.

The first thing that comes to mind is make sure the city water/ fill valve is closed all the way. That is your common denominator for the tank. aside from that there may be some trash in the flapper valve in the pump.

You guessed it, Gordon.  There is a back flow valve inside the pump.  If the problem comes and gos over the season, I would suspect maybe it's got some debris in it.  You can disassemble and clean it in an afternoon.  It may fix it or prove that you need a new one.  Also, if you have a bypass valve for city fill, it may be partially open.

OOOPs! Steve types faster than I do.
Cool!  Thanks Lou and Steve.  I'm hoping it's as simple as my city/tank valve not seated right.  Since it seems to be fine for entire "outings" sometimes and not other times, that would be the most likely cause since I only swing that valve before/after a trip.  I'll crank that back and forth a few times and see if that changes anything.  That's easy enough to do.  If not, I'll pull the pump next.  Appreciate the tips!

Update - I swung the tank fill/city valve to the "city" position and no more pump cycling!  I would leave that valve in either position when I'm not hooked up, so that may be the random factor in why it was an issue sometimes and not others.  Hmph... I would never have thought of that without your tips here.  Thanks, gang!


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