Join Date: Sep 2006
Location: Tampa, FL
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The case of the bilge pump mystery
I came home from a business trip to discover an inordinate amount of water in my bilge. (leaky window, but I'm working on that too) I turn on the battery and flip on the manual pump switch and the pump comes on, but I notice no decrease in water level. I look over the transom and don't see any water flowing out the through hull. Assuming it is a clogged hose or check valve, I disconnect the discharge hose and run water through it with a garden hose, no clog, the water runs right through. Ok, perhaps the pump is too old and needs replacing, I order the replacement from Defender and mount the new pump. The pump works fine, but still won't evacuate the water after an initial surge of liquid. Hhhmmm??
Here is what does happen, with about two or more inches of water in the bilge, I turn on the pump and an initial surge of water rushes out the through hull and then stops, but the pump is still running like crazy. I shut the pump off and wait a few seconds, I turn it back on and another surge of water. As long as I shut it off and turn it on I get that initial surge then nothing. So I disconnect the hose from the pump, turn it on and water rushes through the nipple and back into the bilge at what appears to be the advertised 800 gal per hour. Reconnect the hose and it stops. Ok, now I'm determined to figure this out, so I pull the hose completely out of the boat thinking that perhaps for some reason the height of the through hull in relation to the pump is the problem, (even though it has worked like this for 30 years and was working fine two weeks ago) Gravity, it's not just a good idea, it's the law! So I reconnect the hose to the pump, lay it on the cabin sole and turn it on, only to have the same result. I can blow through the hose, the pump works fine, but I can't get the water out of the bilge without the on, off, on technique.
Anyone want to take a stab at this one?