2003 F36.7 freshwater pump

Jul 28, 2014
6
Beneteau 36.7 Toronto
Our freshwater pump is intermittent about turning off when we shut off the tap. I have checked the diaphragm pump and it's clear. I have tested for leaks in the lines by variously shutting off the tap valves (like the one to the transom shower) with no success. Is the pump pooched or could it be something else?
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Either there is has a leak in the pressure side, or it is starved for water input on the suction side. Clean the filter that should be on the pump. If you have two tanks, make sure you're turned on to a tank that has water in it.
 
Jul 28, 2014
6
Beneteau 36.7 Toronto
Thanks Ron. That makes sense, and you're right - when the tanks are full there is less of a problem. But it still persist intermittently. As far as I can tell, there's no leak on the pressure side. Sometimes there's water sitting in the filter bowl ahead of the pump, sometimes not… Looks like water starved even when the tanks have lots and the supply valves are open...
 
Jan 22, 2008
8,050
Beneteau 323 Annapolis MD
Just rememebered something that would have caused me to buy a new pump- except there was not one to be found. I found in the tank output on my 2006 B323 there is a pretty small check valve that went bad. I gues it is supposed to stop the water from flowing back into the tank. The spring is about what you'd find in a ball point pen. I took it out, and it's been that way for maybe 5 years with no problems. You probably have to put a small Phillips crewdrive in from the outside of the tank and push the valved back into the tank.
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Make sure your transom shower head did not crack (and now leak) over the winter.
 
May 7, 2014
135
Beneteau 390 Tiburon
Thanks Ron. That makes sense, and you're right - when the tanks are full there is less of a problem. But it still persist intermittently. As far as I can tell, there's no leak on the pressure side. Sometimes there's water sitting in the filter bowl ahead of the pump, sometimes not... Looks like water starved even when the tanks have lots and the supply valves are open...
Yes I was embarrassed to freak out about my pump running non stop only to find tank was empty, live and learn
 

arf145

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Nov 4, 2010
495
Beneteau 331 Deale, MD
And I can confirm that a restriction on the inflow side of the pump can cause it to keep running: While replacing all my freshwater plumbing I went with a smaller diameter pipe, which worked fine on the outflow side but was too restrictive on the inflow causing the pump to run incessantly and me to run all over looking for leaks before I figured, and fixed, the cause.
 
Jul 28, 2014
6
Beneteau 36.7 Toronto
And I can confirm that a restriction on the inflow side of the pump can cause it to keep running: While replacing all my freshwater plumbing I went with a smaller diameter pipe, which worked fine on the outflow side but was too restrictive on the inflow causing the pump to run incessantly and me to run all over looking for leaks before I figured, and fixed, the cause.
Thanks Tom.. You may be onto something.. Even if there IS water, topping up the tank seems to make a difference. So perhaps something is gummed up..illing the tank