Bilge pump problems

[Vedat Midilli]

My B43 has 2 electric bilge pumps. One is a Whale diaphragm pump operated manually, other is a Rules 1100 gpm centrifugual automatic pump. Rules has a non return valve on the outlet hose. Though I replaced it, it stucks most of the time. Pump works but does not discharge. I think the problem is pump can not overcome the pressure of the water and may be a possible air lock behind the valve. Rules does not recommend a non return valve but Beneteau has put it for a safety reason. I do not know if the discharge hose has a bend to prevent back siphoning.
In a dry boat if you do not test the bilge pump buy filling the sump with water, it's nearly impossible to notice the pump failure.
Has anybody experienced this problem, and what was the solution?

[Mike Brown]

We have hull #001 and like you have two pumps, the Whale and Rule. Although I haven't inspected the entire length of hose I don't believe there's a check valve in our Rule's discharge line. I've had air locks occur with the Whale, but never with the Rule. Additionally I've seen the Whale back flush but never the Rule. If you can try removing the Rule's check valve and test run it to see if it back flushes. If it doesn't leave it out.

Mike

October Moon

[Vedat Midilli]

Thanks Mike.
If yours have a check valve, it should have been located just about 30-40 cm away from the pump. So it seems they didn't put one to yours. A problem might be the discharge thruhull which is only 15-20 cm above the water line, when heeled can take water in and start a back syphoning. Level of the hose is almost horizontal (if there is not an antisyphon loop somewhere) which can cause a back syphoning.
Without a check valve back flush of the water inside hose can not reach the sump level to trigger the pump. (But very close) Otherwise pump would work continuously.
Vedat

[Mike Brown]

I haven't had any issues with siphoning while motoring or sailing. Note that the Rule has a predetermined run time regardless of the presence of water in the bilge. This ensures any water in the hose is fully evacuated. Probably why I don't have a check valve.
Mike

[Vedat Midilli]

Mike, I agree. Check valve also reduces the flow seriously. Thank you for your comments.
Vedat

[Mike Brown]

Vedat, I had to look in the bilge the other day and decided to look for the check valve for the Rule pump. Yes we have one, just not where I expected it to be. One more thing learned about my boat.
Thanks
Mike