electric bilge pump

[Randy Bates]

My CD25D "Seraph" has an electric bilge pump that drains out the transom. What's aggravating is that after running the pump and getting almost all the water out when I turn it off ALL the water that's remaining in the line rushes back downhill and puts another 1"-1 1/2" or so of water back in the bilge. I tried a "non-reverse" flow valve that uses a small ball that's pushed against a seat, but the pump won't open it. Seems it's designed for the input side of a pump, where the pump pulls the ball off it's seat. Has anyone else seen this and have a cure?



randy.bates@baesystems.com

[Larry DeMers]

You Bet! This is common, and the fix is cheap..but may be a bit of work. You have to get inside and raise the absolute level of the bilge pump output hose up to the bottom of the cockpit floor. DO this as close to the pump as practicable. What you have created by doing this is to create a high point in the water flow whcih acts as a siphon break, so that under normal circumstances water being pushed out the tube will go over the bump in the hose nicely. When shut off, the water will try to get siphoned back to the bilge, but will succeed in getting only the amount in the hose up to the siphon break (hump). The rest will slowly dribble out the transom thruhull.

What I have done is to use several large wireties with the screw hole in them. Encircle the hose with the wire ty, and then pull the hose up as high as it is possible to go, and attach the wire ty to the nearest wood frame or bulkhead.

It may indeed take 4 wire ties to make that hose sit as high as possible..but do it. Believe me, you will appreciate it. Keep the bump in the hose an actual 'bump'..ie: that is, raise that section of hte hose as high as you can, but keep the remaining hose level..and lower than the bump by a good margin. This will ensure that you get a minimum or return water back after the pump was shut down.

Remove that one-way valve...you **really** do not want one of any description in the bilge path unless you have no choice. It reduces the pumps output even more, and debris gets trapped in the valve sometimes, which will not help flow either.

Cheers,

Larry DeMers
s/v DeLaMer
Cape Dory 30

My CD25D "Seraph" has an electric bilge pump that drains out the transom. What's aggravating is that after running the pump and getting almost all the water out when I turn it off ALL the water that's remaining in the line rushes back downhill and puts another 1"-1 1/2" or so of water back in the bilge. I tried a "non-reverse" flow valve that uses a small ball that's pushed against a seat, but the pump won't open it. Seems it's designed for the input side of a pump, where the pump pulls the ball off it's seat. Has anyone else seen this and have a cure?

demers@sgi.com

[Randy Bates]

Thanks Larry.
Randy CD25D "Seraph"

You Bet! This is common, and the fix is cheap..but may be a bit of work. You have to get inside and raise the absolute level of the bilge pump output hose up to the bottom of the cockpit floor. DO this as close to the pump as practicable. What you have created by doing this is to create a high point in the water flow whcih acts as a siphon break, so that under normal circumstances water being pushed out the tube will go over the bump in the hose nicely. When shut off, the water will try to get siphoned back to the bilge, but will succeed in getting only the amount in the hose up to the siphon break (hump). The rest will slowly dribble out the transom thruhull.

What I have done is to use several large wireties with the screw hole in them. Encircle the hose with the wire ty, and then pull the hose up as high as it is possible to go, and attach the wire ty to the nearest wood frame or bulkhead.

It may indeed take 4 wire ties to make that hose sit as high as possible..but do it. Believe me, you will appreciate it. Keep the bump in the hose an actual 'bump'..ie: that is, raise that section of hte hose as high as you can, but keep the remaining hose level..and lower than the bump by a good margin. This will ensure that you get a minimum or return water back after the pump was shut down.

Remove that one-way valve...you **really** do not want one of any description in the bilge path unless you have no choice. It reduces the pumps output even more, and debris gets trapped in the valve sometimes, which will not help flow either.

Cheers,

Larry DeMers
s/v DeLaMer
Cape Dory 30

My CD25D "Seraph" has an electric bilge pump that drains out the transom. What's aggravating is that after running the pump and getting almost all the water out when I turn it off ALL the water that's remaining in the line rushes back downhill and puts another 1"-1 1/2" or so of water back in the bilge. I tried a "non-reverse" flow valve that uses a small ball that's pushed against a seat, but the pump won't open it. Seems it's designed for the input side of a pump, where the pump pulls the ball off it's seat. Has anyone else seen this and have a cure?

randy.bates@baesystems.com

[Pete]

WOW!!! My bige pump will cycle because of the of the back flow coming back in the bilge. I'll give this a shot. Will post my results.

THANKS

Pete



svmiranda@aol.com

[Randy Bates]

Yesterday I put the recommend "loop" into the discharge line. I took it as high as it would go up under the galley sink. I now get about 1/2 inch of backflow instead of the 1-1 1/2 inches as before.

Thanks again Larry

You Bet! This is common, and the fix is cheap..but may be a bit of work. You have to get inside and raise the absolute level of the bilge pump output hose up to the bottom of the cockpit floor. DO this as close to the pump as practicable. What you have created by doing this is to create a high point in the water flow whcih acts as a siphon break, so that under normal circumstances water being pushed out the tube will go over the bump in the hose nicely. When shut off, the water will try to get siphoned back to the bilge, but will succeed in getting only the amount in the hose up to the siphon break (hump). The rest will slowly dribble out the transom thruhull.

What I have done is to use several large wireties with the screw hole in them. Encircle the hose with the wire ty, and then pull the hose up as high as it is possible to go, and attach the wire ty to the nearest wood frame or bulkhead.

It may indeed take 4 wire ties to make that hose sit as high as possible..but do it. Believe me, you will appreciate it. Keep the bump in the hose an actual 'bump'..ie: that is, raise that section of hte hose as high as you can, but keep the remaining hose level..and lower than the bump by a good margin. This will ensure that you get a minimum or return water back after the pump was shut down.

Remove that one-way valve...you **really** do not want one of any description in the bilge path unless you have no choice. It reduces the pumps output even more, and debris gets trapped in the valve sometimes, which will not help flow either.

Cheers,

Larry DeMers
s/v DeLaMer
Cape Dory 30

My CD25D "Seraph" has an electric bilge pump that drains out the transom. What's aggravating is that after running the pump and getting almost all the water out when I turn it off ALL the water that's remaining in the line rushes back downhill and puts another 1"-1 1/2" or so of water back in the bilge. I tried a "non-reverse" flow valve that uses a small ball that's pushed against a seat, but the pump won't open it. Seems it's designed for the input side of a pump, where the pump pulls the ball off it's seat. Has anyone else seen this and have a cure?

rtbates@austin.rr.com