Thanks Ken . Good info . I especially like the idea of a clear test hose to isolate whether it’s the pump or my outflow . If the rule pumps do get primed if the water level in the outflow hose gets high enough, then my system -should- work .RE: Ken, I'm curious how your system will prime. If you dry out your bilge (including the water that flows back form the outlet hose - assuming you don't have a check valve), - I do not have a check valve
then there is no water in the pump outlet. - correct, only air in the bilge, pump, and hose.
If you manually fill the bilge (say with a bucket or two of fresh water; enough to trigger the float switch), does it still work? - yes, whether I fill it with water, or water flows in from the mast, or water floods up from a leak, the pump works when the float is triggered, even though it was dry to begin with.
It doesn't seem like it would.....but maybe I am wrong in my understanding of how the Rule pumps are designed. -
A. Start with a dry bilge and an empty bilge hose. How do you really know if your hose is empty? (1) Disconnect it and blow air through it--Did you feel any trapped water in the line? Or, (2) disconnect the existing hose and hook up a test hose from the pump to your sink or your cockpit--a clear hose is better so you can see what is happening.
B. Start filling the bilge with water. As the water level water rises, water need to pass through the pump, past the pump blades and pump outlet (even while the pump is unpowered) and into the bilge hose. The water level in the bilge hose has to rise to the same level as it is in the bilge itself. As long as this happens, the pump blades are in full contact with the water and are, therefore, primed. The pump will move water when activated. Or,
C. If you add water to the bilge, but the water level is not simultaneously rising in the bilge hose, this means you have air or water trapped somewhere in the hose (like the Rule "airlock" video). If the water has not risen in the bilge hose, then water has not passed from outside the pump, past the pump blades and pump outlet, and into the hose--meaning the bottom of the pump case is still full of air (even though the bilge is full of water). When the float switch triggers, the blades will spin around and splash against the trapped air and water but will not pump water through the hose. In other words, until the pump is activated, the bilge hose needs to act as an air vent for the pump--it vents the air from the bottom of the pump case as the pump case begins to fill with water.
View attachment 36950 Water level rising in bilge, pump, and hose before bilge switch triggers.
Other than the slight dip mentioned, i don’t see any obvious problem. I didn’t actually try to blow air in the outflow hose , but I’ll try that. I did connect a garden hose to it ( with a brass garden hose coupler) and water flowed through it fine . There must some back pressure in line somewhere causing the airlock . I’ll try your diagnostics next time I’m at the boat. I’d like to prove that it works with a test hose. If that works , then I know it’s a problem downstream .
Ps: I wonder about danger of not having a check valve . Do you have any siphoning issues at different points of heel ?