Relay menu missing on Cerbo GX (GUI-v2 / Venus OS 3.79) - Cannot set Relay 1 to Manual for Node-RED

Been setting up Node-RED on my Cerbo GX to handle some custom automation for the garden office — basically want to control Relay 1 based on a combination of SOC thresholds and load spikes rather than relying on the built-in generator logic.

Running Venus OS Large 3.79 with GUI-v2 and I've hit a wall. The Relay menu that used to be under Settings seems to have either moved or gone completely missing. Can't find anywhere to set Relay 1 to Manual mode, which from what I understand is a prerequisite before Node-RED can actually control it via the victron-output-relay node.

On the old GUI you could just go:

• Settings → Relay → Function → set to Manual

But in GUI-v2 I'm not seeing that path at all.

Few questions:

1. Has anyone else lost this menu after upgrading to 3.79 / GUI-v2?
2. Is there a workaround — maybe setting it via the dbus directly or through a Node-RED inject on startup?
3. Or do I need to drop back to the classic GUI temporarily just to configure it?

I've tried poking around in Remote Console as well with no luck. The relay itself works fine — I can hear it clicking when the system does its own thing — so it's purely a configuration access issue.

Would rather not roll back the firmware if I can avoid it. Anyone cracked this on a recent Venus OS build?

@CamperEwan This bit me badly last year when I upgraded to Venus OS 3.x on my Cerbo. The Relay menu genuinely disappears from the GUI-v2 interface in certain firmware builds — it's not your imagination going sideways.

The fix: SSH into the Cerbo and manually set the relay function via dbus:

dbus -y com.victronenergy.system /Relay/0/Function SetValue % 2

Value 2 = Manual mode. Once set via dbus, Node-RED can toggle it properly through com.victronenergy.system /Relay/0/State.

Alternatively, drop back to the old GUI temporarily (Settings → General → GUI) — the Relay menu reappears there like magic.

Victron's Venus OS large build also sometimes resolves it. Worth checking the Victron Community forums too — there's a sticky thread specifically about GUI-v2 relay regression in 3.7x builds.

@Titch is right that it's a known regression, but there's a workaround that saved me when I was doing something similar for EV charging automation on the boat.

SSH into the Cerbo and set the relay function directly via dbus:

dbus -y com.victronenergy.system /Relay/0/Function SetValue %0

That forces it into manual mode even without the GUI option showing. Once it's set, Node-RED can toggle it normally via the dbus node.

Worth double-checking with dbus-spy afterwards to confirm /Relay/0/Function is actually reading back 0 — I've seen it silently fail on first attempt.

The GUI menu seems to reappear after a full Cerbo reboot on some firmware builds, but don't rely on it persisting through updates.

@CamperEwan Worth knowing that even once you've got the relay showing again, if you're driving it from Node-RED you'll want to set the function to Manual via the com.victronenergy.system service rather than fighting the GUI. I do mine through the dbus node directly — write 0 to /Relay/0/State and make sure nothing else in Venus OS is trying to claim that relay (generator autostart is the usual culprit nicking control back off you mid-automation). Caught me out during my van build when my Node-RED flow was working perfectly then randomly stopped — turned out the generator logic was overriding it. Disable any conflicting relay functions first, then set Manual mode.

Had this exact headache on my static when I first started poking around with Node-RED flows. One thing nobody's mentioned yet — if you're SSH'd into the Cerbo anyway, you can set the relay mode directly via dbus without needing the GUI at all:

dbus -y com.victronenergy.system /Relay/0/Function SetValue %3

Value 3 is Manual mode. Saves faff if the menu's playing silly beggars. Double-check with a GetValue afterwards to confirm it stuck — I've had it revert after a Venus OS restart before, so worth building a startup node into your flow to re-assert the mode on boot.

@RussGreen makes a good point about the write permissions side too, that one caught me out for ages.