After paying the $2000 plus dollar bill at the marina for engine and bottom work I headed out for the 6 hour trip home in the humidity and rain trying to beat Wilma. After motoring for about 90 minutes I set the autopilot and went below for a cold drink, I was shocked to find a foot of water thru out the cabin. 1st thought was to check the thru hulls, they were ok. 2nd thought was to check the hoses and stuffing box that had just been replaced,they were ok. 3rd thought was to check the bilge pump.... not working,... blown fuse! After scrambling to find a fuse, I replaced it and the bilge pump starting pumping the water out. But where did all this water come from? After everything checked out ok and the now working pump had done its job I started for home leaving the wet carpet on deck and the fake wood bilge cover off, so I could watch the pump like a hawk. That's when I noticed the pump was cycling off and on, as it turns out {some of you have guessed} the stern discharge hose {when motoring} is below the water line causing a siphon, when the fuse blew on the pump it was like having a hole in the boat and all that water was coming backwards thru the bilge pump. I know a check valve isn't a good idea, do they make a anti-siphon bilge pump? Anyway, I am glad to be home, having a tall one and waiting on Wilma. Thanks in advance for any positive ideas, Jack
TODAY WAS A BAD DAY
- Thread starter Jack2438
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Pur a rise in the discharge hose.
Shaped like an upside down U. That is what I have done. Good luck.
Shaped like an upside down U. That is what I have done. Good luck.
Vented Loop
I am pretty sure that you need to add a fitting called a "vented loop" to the top of upside down U in the line. Else a siphoning action will just draw water over the loop - thats what siphons do - draw water up and over a loop to a lower place. The vented loop acts as a siphon break. Take this over to the "Head Mistress" forum on this site - Peggy will know the answer for sure. The link below is to the Defender Marine page with a listing of these parts. Best o' Luck, OldCat
I am pretty sure that you need to add a fitting called a "vented loop" to the top of upside down U in the line. Else a siphoning action will just draw water over the loop - thats what siphons do - draw water up and over a loop to a lower place. The vented loop acts as a siphon break. Take this over to the "Head Mistress" forum on this site - Peggy will know the answer for sure. The link below is to the Defender Marine page with a listing of these parts. Best o' Luck, OldCat
thank you
After a good nights rest I went down to look at the boat.Of coarse the fresh water pump was shot after being submerged in salt water but everything else looks Ok. In the stern lazarette {were the cng tank is} is the loop{upside down u} that you both had mentioned. There is not a vent in the top so off to WM for more stuff. Thanks for pointing out what I need to get. By the way, there is a vented loop for the engine exhaust but not for the bilge. Whats up with that? thanks again for your help. Jack
After a good nights rest I went down to look at the boat.Of coarse the fresh water pump was shot after being submerged in salt water but everything else looks Ok. In the stern lazarette {were the cng tank is} is the loop{upside down u} that you both had mentioned. There is not a vent in the top so off to WM for more stuff. Thanks for pointing out what I need to get. By the way, there is a vented loop for the engine exhaust but not for the bilge. Whats up with that? thanks again for your help. Jack
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