We install Rules on the 300+ Harbor 20 daysailers. We selected these after some extensive review of all the small pumps. We do not install Rules on the larger boats.
About 97-98% of the H20 owners love the pumps (if one can ascribe love to something as prosaic to a pump). They find them reliable and never have to worry about them.
However ,about 1-2% of the Harbor 20 owners dislike them with a ernest & vocal passion. (insert salty language)
As a result, we have learned more than we'd ever want to know about the minutia of small bilge pumps. We had one of the Engineering guys at the company write a full blown report on the pump and its competitors. Rule, despite its limitations remains the best solution at this time. Rule has been helpful and quick to respond to our requests, but a 1-2% unsatisfied rate is outrageous and unacceptable. So we have been struggling with the subject for some while.
They operate differently than typical mechanical float switch pumps in that their electronic 'float' switch turns on when the impeller encounters mechanical resistance. (ie a water load) The Rule pump switches on every few minutes to turn the impeller -
A) no impeller resistance = no water = pump turns off
B) impeller resistance = water = pump runs until impeller resistance ends
There is a nice mesh screen at the base of the pump designed to keep out leaves and debris from providing false positives. However, sand or other fine grit can accumulate at the impeller and load it up = false load = pumps runs 4ever = burned out rotor = boat filling with rain water = angry boat owner = salty language
The Rule pump sits very low, so it can suck out nearly every last drop of water in a sump/bilge. The Rule manual states 'No Check Valves !' - so depending on the design of your system, you may be cycling water back to the Rule pump in an endless loop. ( see equation in prior paragraph)
In 2012, we are going to try and collect data on the 2% of owners who experience consistent failure. There is likely a recognizable root cause which a bit of corrective action might solve.
Last edited by WDS123; 12-26-2011 at 10:49 AM.