Bilge Pump Switches; My Special Nightmare.

Jim Dolan and I had a discussion about a bilge pump repair that went awry and almost simultaneously we expressed frustration about the bizarre variety of bilge pump control installations in boats.

We commiserated that in sinking investigations it was always a puzzle to actually figure out how the bilge pumps were configured and especially how the pumps were switched. Often the crew was not sure themselves before and after the accident as to how these pumps were switched. We quickly noted that the switch configurations in our two personal boats are completely different (and also far from perfect).

It is rather bizarre that something as vital as a bilge pump is not obvious in its switch and indicator design and therefore becomes a puzzle the moment it starts to play a part in an emergency (or becomes an emergency because the pump was not switched to the position the user intended).

While ABYC has a bilge pump standard, the standard does not specify the switch and indicator arrangement, including the positioning of breakers and fuses.

Good switch and indicator design, which includes breakers and fuses, is most vital for the most vital equipment and, somehow and too often, it is missing with bilge pumps.

At the most basic switch level, a bilge pump should have an automatic mode, a manual mode, and an off position, but the off position should be clearly visible.

Like all electrical equipment, the wiring should be properly fused or breakered and easily indicate that the fuse has failed or breaker has tripped.

A fuse in a vital system is inherently a poor solution, since one needs to remove a fuse to see if it has failed and that is probably the last thing one wants to do when the water is rising in the bilges. To say nothing of searching for a fresh fuse if it looks like it has failed (and to have it fail again to indicate that there is actually a wiring short and it is time to break out the bucket brigade, or the life jackets.).

While it is a little scary to have a manual constant-on switch (since dry running a pump is bad news), a momentary manual switch may be the last thing you want to have aboard when for some reason the pump has to be manually activated and you have to work in the bilges to stop a leak. As such, momentary manual switches are a no-no. Having said that, a reasonable solution to accidental manual engagement of the bilge pump is to have a friendly intermittent beep when the bilge pump is running. It would be great if this were an industry wide standard beep pattern since anybody on a boat, or on the dock near a boat, hearing such a beep would know there is a bilge pump running (whether in auto mode or manual mode).

While not absolutely required, a bilge pump counter is a nice feature to remove doubt about any number of issues.

A simple search for bilge pumps switches provides an astonishing array of possibilities and configurations.

In picking through the internet pictures I came across an article on bilge pumps by Steve D’Antonio (and actually copied some of the switches in his article). While he does not fully address my special nightmare, I think it is one of the best articles on the subject and worth a read.

The best known arrangement is this switch:


It is a true classic, with a clear indication as to what the setting is, but has two fatal flaws and a number of minor flaws. The first fatal flaw is that it has a fuse instead of a breaker. The second fatal flaw is that the manual switch is intermittent.

The first minor flaw relates to the indicator light. It goes on when the pump is running, but it does not clearly state that. An indicator light should always state the condition it indicates. In this case the light should have a caption above it stating: “Pump Running”.  This switch also does not show a fuse failure.

This switch would be much improved if it had an indicator for the Auto mode. This should be a small green indicator to the left of the “Auto” indicator.

When the pump is breakered, this small green indicator will be off when the breaker is tripped. In other words, when the green light is on, things are good and when the green light is off, they are not.

Such a switch arrangement is also self training. What that means is that an innocent bystander can reasonably conclude the proper setting by experimentation in whatever position the switch is set. A person can turn the switch to “off” and there are no lights. They can turn it to “manual” and there is a red light, they can turn it to auto and there is a green light. At that stage it becomes easy to conclude that if the pump runs in “auto” the red light is on too.

While it is neat to have a nice row of matching switches on your console, bilge pump switches should be separate from other switches to prevent them from being confused with other switches that are switched on and off on a regular basis.

With regard to the breaker, it makes sense to fit the bilge pump breakers with separate covers and a note on the panel to leave the bilge pump breakers on at all times.


There is one additional potential improvement. A toggle switch setting can be changed by accidental contact. A preferable switch would be a rotary selector switch, which provides a strong visual indicator and is difficult to disturb by accident.

The question is does such a switch panel exist?

These are samples of switches I have found. I will let the reader judge how good or bad they are.






Meanwhile, as far as bilge pump switches are concerned, someday I hope to see a standard switch arrangement that follows these rules:

  1. 1. Red light means pump is running
    1. 2. Green light means “Auto” mode is engaged
  2. 3. Intermittent “Beep” means pump is running

4. Rotary selector switches

5. Breakers only, no fuses

6. Bilge breakers have covers on the breaker panel

7. No hold down manual mode

8. Arrange bilge pump switches in a separate area of the console

9. All indicator lights should be labeled to show the condition they indicate

10. A bilge run counter is nice to have

Now all I have to do is find the time to fix the bugs on my boat. At least I now know what the bugs are.