Posted by Peter Kennedy on 12/16/2025 to
System Integration
It is possible to use your Victron Cerbo GX as a bilge monitor. There are two ways to set it up, one with a dedicated float switch that works as a high water alarm, and the other way is connected to your existing bilge pump, where it is more useful as a bilge counter. You can even do both. Because these alarms get recorded by the Cerbo and because the Cerbo can be connected to the Victron VRM remote portal you can view the results online even if you are away from the boat. You can even set it up to send push notifications to your phone. Lets look at how this is done.
We will be using the Cerbo Digital Inputs for this. The Cerbo has four digital inputs, each is a two wire connection. The Ekrano only has two digital inputs. These inputs can accept an open or closed signal, such as would be available from a float switch. They cannot however accept a 12 volt signal from a bilge pump. The voltage limit on the input is 5.0 volts. So to connect the Cerbo direct to your bilge pump you need an intermediate device.
HIGH WATER ALARM
This is the easiest to do. Install a float switch in your bilge a bit higher than the bilge pump. Connect it to one of the digital inputs as shown below. This would be used as an alarm only and the float switch would be a bit higher than your bilge pump so it would only alarm if the bilge pump stopped working or couldn't keep up..
BILGE COUNTER
The other way to do this is to connect the Cerbo direct to your bilge pump. We already said you can't connect 12 volts direct to the digital input. In this scenario we need to use the Victron Energy ASS070300100 Orion-Tr Isolated DC-DC Charger remote cable to convert the 12 or 24 volt signal we are getting from the Bilge Pump to an On-Off signal that the Cerbo can accept. The wiring diagram is as shown below. This method is more suitable to use as a bilge counter so you can keep track of how often your bilge pump runs.
CERBO SETTINGS
Once you have the physical wiring installed you have to tell the Cerbo what you have done. This is done in the Cerbo menu at SETTINGS > INTEGRATIONS > PHYSICAL I/O > DIGITAL I/O and the start looks like this:
In this case we have enabled two inputs, one for an Alarm and one for Bilge Pump Counter. The screenshots came from an Ekrano which only has two digital inputs, the Cerbo has four. Here is what they look like:
The next screenshot shows where you get to select the function of the input:
If you set up your input as an alarm the Cerbo will alarm when the input is triggered. This Blog Post from Victron tells you how to set up push notifications to your phone. If you set the input up as a counter the screenshot below shows you what you get. The screenshot is taken from the VRM. This information does not show up locally on the Cerbo.
Peter Kennedy has been in business since 1991 designing, installing and servicing marine electrical systems. The purpose of this blog is to offer support to both professional installers and do-it-yourself boat owners who wish to undertake this work themselves.
SEARCH
You can subscribe to get automatic notifications of new blog posts, this is separate from a newsletter subscription.
