Very strange water pump issue

[TBird]

Last weekend, I filled my water tank completely. While at sea, I tried to run my fresh water pump and it wouldn't work.

When I went to the boat today, I was surprised to find that (1) the water tank was empty and (2) the pump is working. I am pretty sure the pump was turned off all week. I again filled the water tank, and now the pump doesn't work.

How can this be? I assume that, if somehow the water came out of the faucets, it would collect in the holding tank, but the holding tank is empty. No water in the bilge or transon locker either. Could there be a relationship between the tank being completely full and the water punp not working?? I imagine there is some sort of valve that keeps the water from flowing back into the tank; maybe the pressure created by the tank being full is somehow affecting that mechanism??

 

[sbw1]

You may have a leak in the plumbing and the water leaked into the bildge and was pumped out by your bilge pumps. The fresh water pump ran dry and died.

 

[TBird]

You may have a leak in the plumbing and the water leaked into the bildge and was pumped out by your bilge pumps. The fresh water pump ran dry and died.

Maybe, but the pump was running fine today until I refilled the tank.

 

[dpvandy01]

Last weekend, I filled my water tank completely. While at sea, I tried to run my fresh water pump and it wouldn't work.

When I went to the boat today, I was surprised to find that (1) the water tank was empty and (2) the pump is working. I am pretty sure the pump was turned off all week. I again filled the water tank, and now the pump doesn't work.

How can this be? I assume that, if somehow the water came out of the faucets, it would collect in the holding tank, but the holding tank is empty. No water in the bilge or transon locker either. Could there be a relationship between the tank being completely full and the water punp not working?? I imagine there is some sort of valve that keeps the water from flowing back into the tank; maybe the pressure created by the tank being full is somehow affecting that mechanism??

At least on the 280 the water from the sinks drains overboard not in to the holding tank.

 

[Hampton]

At least on the 280 the water from the sinks drains overboard not in to the holding tank.

Same on mine and most others out there, unless they have been rigged for certain lake operations (see related thread). Maybe you need to adjust the pressure switch (or whatever it's called). There should be a screw on the side of the assy near the water pump that you can adjust to change the pressure level at which the pump comes on.

 

[TBird]

I'm not aware of any special rigging on my boat, so it probably does run off into the water. I may have left the water pump on and it ran out through an open faucet when the pump kicked on.

I'm still left with the problem of a intermittently running pump which might be a loose wire or something, I'm going to poke around today.