Norm, I'm not sure how a manual on/off switch would solve the problem. Isn't the issue really how high the pump discharge is from wherever discharge water ends up? My thinking is that if the discharge end of the hose is sufficiently below the pump then there wouldn’t be any backflow since gravity or head pressure should completely empty the hose.
I'd think the only way to eliminate the issue would be not only a "run dry" pump, but a pump strong enough to push sufficient air through the hose to "push" the remaining water completely out of the hose into whatever it goes to, either an above waterline thru-hull or a really, really deep bilge or something. S Steve Weinstein S/V CAPTIVA 1997 Hunter 376, Hull #376 Sailing out of Oyster Bay, NY All outgoing mail protected by VIPRE A/V -----Original Message----- From: [email protected] Sent: Thursday, April 12, 2012 10:12 AM To: [email protected] Subject: Re: [Liveaboard] How often do you clean your shower sump... My shower sump consists of a well in the floor of the shower (all fiberglass over styrofoam) with a perforated sheet (the screen) of stainless covering it. The pump - one of those square Rule pumps - and float switch are in the sump. I like this pump because it is square and so fits the square well well, and the pump motor/impeller is easily removable for replacement without disturbing the plumbing. I clean the sump when the pump stops pumping properly and I have to go into it for service. I clean the screen whenever I notice debris (mostly hair) accumulating. Most of the trouble I have is with the float switch so I am adding a manual-off-auto switch (it's on the List). Another problem is that the sump is so small that the "fall back" of water returning to the sump after the pump shuts off raises the float to almost the point of turning on the pump again. A check valve (prone to fouling with hair) or larger sump (too much work) or manual switch (on the List) would be the cure for that. Norm S/V Bandersnatch Lying Julington Creek FL _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://liveaboardonline.com/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardonline.com/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
