Phantom pump counts and an internal red light

I recently installed a FloatHubN2K WiFi + Cellular (LTE North America). Currently, the only things I have connected are power (via the DC IN screw terminals) and my house battery. The GPS gets a fix intermittently, so I’m planning to install an external GPS antenna.

My issue is that pump counter 2 and 3 (primarily 3) are incrementing on the web interface even though nothing is hooked up to those inputs. I’m not sure how to go about troubleshooting this.

Separately—or maybe relatedly—I noticed that there is sometimes a red flashing light coming from insight the upper right of the box. (I.e., not the Network and GPS indicator lights, but rather something inside that is shining through the plastic casing.)

We’ll have a look and update you shortly.

The internal red light (inside the case) is from a debugging LED on the GPS daughter board. It indicates a good fix (one flash every second). Should not be related to any pump readings.

We are definitely seeing messages from the devices indicating pump activity. If you go here:

and then scroll all the way to the bottom to the table titled “Most Recent FHB (Pump) Messages by Order of Reception at Server” you can see the data the device is sending.

The pump sensors are the top 3 screws of the screw terminal block. They just look for voltage above ground and when they “see” that, generate a pump “on” event. When the voltage falls back down to ground, that’s a pump “off” event.

If you could double check that there is no stray wire from the DC-in line, the house battery hookup, or other nearby wiring that might be intermittently contacting any of those terminals, that would be useful. If you can’t find any external explanation, then it is likely a device failure. Happy to ship you out a replacement with a return mailer for the original unit if need be.

Appreciate you taking a look. There isn’t much else around the box, so I don’t think there is going to be any nearby wiring that is intermittently making contact. That said, I will take a look when I’m down at the boat next (later this week) and get back to you. Thank you again.

Ok, let us know if you spot anything.

In the meantime, you can have the main interface (and alerting, etc.) ignore pump 3 by going to:

and un-ticking the “In Use” checkbox for Pump 3.

Fyi, i see the same phantom reports. Id assume connecting the unused pump input to gnd would eliminate this. For now i ignore my one unused input.

Thanks for the feedback, much appreciated. That’s 2 units displaying the same behavior, and both are relatively recent N2K units (which use newer microcontrollers). We will do some testing at our end.

I took a look at the unit today on the boat. I don’t see anyway that stray wiring could be making contact, see the attached picture. If I wasn’t planning to use at least two of the pump inputs, I would be happy just to turn them off, but my intent is to hook up my bilge pump plus a high water alarm. That said, if you want some time to dig deeper on your end before shipping a replacement that’s fine with me.

Definitely think we should send you out a replacement unit. Can you confirm your shipping address is still current (by support email)?

One interesting thing to note is that the phantom pump activity seems to be related to activity on the N2K bus. No idea why this would be the case, and that may just be another indication of a internal hardware/signal issue.

For example, something changed on your water temp measurements on July 23:

And right around the same time the phantom P3 measurements shot way up:

Again, no idea if/how these are related, but just noting it in case someone has seen something similar.

That is interesting. I replied to the support email thread with my mailing address. It should hopefully match what you have on file for my account.


I got the new unit installed about two weeks ago. Thanks for sending it out; I’ll get the old one sent back this weekend.

Unfortunately, I’m still seeing the same behavior. Nothing is hooked up to the pump connections, but the unit is showing that the pumps are cycling.

In each case, the cycle seems to be one second long. I’m wondering if there would be a way to put a threshold on the pump counters so that they don’t count cycles that are one second or less.



Just to confirm you have nothing hooked up to any of the three pump inputs?

Do you have any tank or voltage monitors on your N2K bus? Could you disconnect the N2K bus for 24-72 hours so we can see if that has an effect on the phantom pump counts?

Sorry for the issue, looking forward to getting to the bottom of it.

I do not have any tank or voltage monitors on the NMEA 200 bus. But, I went ahead and disconnected the NMEA 2000 connector–it’s been off for about two weeks. The phantom counts are continuing. The only thing connected right now is power and the voltage monitor for battery 1.

Thanks for conducting the experiment, it’s much appreciated.

This is really interesting, but I’m afraid we don’t have a good explanation for the behavior. Normally we would just send you out a replacement unit, except, of course, we’ve already done that. So two options at this point:

  1. We can add a filter to your input data routines at our end to take out any pump cycles that are 1 second or less. We ran a test case and this would remove all but 2 of your pump cycles (there were two times that your pump 1 ran for about 12 seconds, both on September 8).

  2. We can update the firmware on the device itself to test for a higher voltage (current threshold for “pump on” is 2 volts) and see if that makes any difference (we would need to send you out a new replacement device after we have made the changes).

We are going to start work on both of these, but let us know your preference. We could do 1 as a pilot, where we would back up your data each time so we could revert it all if there was an issue with messing up any “real” data.

Let us know what you think, and sorry again for all the issues with pump signals.