Why I learned to hate automatic bilge pumps

Manual bilge pumps are controlled by a separate float switch that turns the pump on and off when water levels rise and fall. Electronic automatic pumps measure current draw while the motor is spinning, and infer water levels from that. This means that the design of a typical electronic automatic pumps require it to turn on for a few seconds, every few minutes, to permit that measurement. When the pump spools up with no water load to carry, current draw is very small.
In this video, we use an oscilloscope to document current waveforms and exactly diagnose the failure mechanism of a RULE 27SA automatic bilge pump in a boat. We discuss the design considerations that make this style of pump prone to component failure, and we convert a boat with an automatic pump to a manual Rule 27DA pump controlled by a separate Rule 35A float switch.
i go on to break apart the pump and document the failed component inside. In a prior video three years ago, when an identical pump failed, I showed a similar presentation, with a different cause of failure and a different diagnostic pathway. That old video is still worth a look, to show an overall view of the system, to show how to inspect the anti-siphon valve, and to see the breadth of other diagnostic tests you may find useful. That video is here
• Marine Bilge Pump Trou... .
This is an amateur presentation, offered in good faith, for free, but with no guarantees as to safety or accuracy. All DIY repairs come with risks, both to the individual, his property, and potentially risk to others. Any misadventure you encounter if you decide to accept the risk of DIY repair is on you.

[@billk5727]

Nice upgrade with video documented procedures! I believe your set up with the float switch is a better way to go.

[@tylerdrown]

Another great video, you are my favorite TH-camr. I’m about to replace another one of these integrated automatic pumps with a separate switch and pump.

[@davidpawson7393]

Thank you for the lesson. Nice job too.

[@apackwestbound5946]

Great diagnosis and explanation!

[@roughas100]

I was using cheaper float switches, guessing Chinese copies of Rule , found they got stuck in the up position at the hinge point , maybe just a few grains of sand , who knows . Ended up hot gluing a bit of closed cell foam to the top of the paddle with a small bit of lead glued to the foam too, gave the switch more mass to go back down . Seen someone else use cork but I'm not a wine drinker ..... found it made the switch operation a lot more reliable and no real change to the turn on / off water levels.
Thanks for the video showing the normal and unhealthy pumps on the graphs , had no idea a bad pump would look that noisy .

[@janots739]

Awesome sailboat ⛵️ videos, explaining intimidating concepts and problems encountered

[@JL-se1dp]

Those automatic pump that sense water every few minutes only good for a short while. Tons of problems. Now I changed all to float switch and automatic water sensing switch

[@SVImpavidus]

I hate those type of pumps. We did a video ages ago about having independant alarms and manual switches as well as automatic. Great video. I think we are both of the same mind. Sail Safe mate. Ant & Cid

[@jeffieh]

Great vid, thanks. I learned a lot.

[@k1mgy]

Nice work with the scope. What was the current interface you used to get those waveforms please?

[@spelunkerd]

The Pico red inductive 60A probe came with the old 4425 Pico interface I got several years ago. It connects to the interface with a standard B&C connector. It's certainly fine for my use although one would always like the upgrades with newer models. You don't need this kind of professional style automotive scope to get waveforms, especially if you just want a quick look without having to record waveforms. There are Chinese scopes for sale on Amazon that are in the hundred dollar territory, and inexpensive current probes with less sensitivity can be found, too. Pico also sell less expensive scopes that seem to be popular. Thanks for stopping by!

[@svcoquina114]

I get the same life from Rule switches as the automatic pump: 3 year. Its best to get a Ultra switch.

[@mgevirtz]

Thank you

[@jimpetty2961]

keepem coming