Where do you choose to have a fixed IP? In the toolkit, in enlighten, in a web raised in the IQ Gateway? Thanks in advance!
I just contacted Enphase again, they are not willing to solve the issue for a few days as they did earlier in my installation.
They still say that this is caused by the current firmware version D8.3.5289.
And they are actively working on it, so some positive news from Enphase.
Hopefully they fix this soon!!
George
Connect to https://envoy.local/login.html
Authenticate with a token (instructions or here). Not easy as it was before.
Wait a second or two.
Click Ethernet and set a fixed IP address.
Please do not discuss about this into this thread.
Great, you are connected again! I hope that it is a permanent fix. Regards Rene
I fired up wireshark and it seems that the Enphase cloud aka backend has to allow port 502 to open up. The minute I disconnected the IQ Gateway from Internet…modbus failed again.
Can’t confirm.
Did disconnect the router from the outer world for 35 minutes and Modbus stayed active / was communicating with venus OS.
Interesting. Seems like I’m back to yet another call yet again.
I believe that if Enphase implements Modbus TCP communication according to the SunSpec certification, it should be an option enabled by default permanently or an option that can be activated by the installer. Having to make a request through technical support seems like a workaround for a system under testing, not a definitive solution.
I also get the impression that they are not providing a real answer to the problem, as none of the responses I have received or read seem to address the actual issue. It feels more like an evasive response to avoid acknowledging the real problem.
In summary, the system had been working correctly for almost a year with a static IP and Ethernet, and without modifying anything, it stopped working on 05/27/2026. After numerous calls and emails, it remains unresolved in my case to this day.
Could you still ping to the enphase envoy (does the giver IP by the router still work)?
If yes I noticed something strange.
The system is seen as VRM instance 21 at the begin of activation to switch to VRM instance 20 somewhere after 1 day.
The product name also changes can’t see ID 21 anymore buy product name ID 20 is “ENPHASE ENERGY Enphase IQ Envoy”
Under PV inverters in Remote control I see 2 PV inverters one with name - and one with the envoy serial number.
Maybe this is this the old and new Modbus enphase talks about?
Just FYI, most of the posts up here are slightly to technical for me. Just of the phone w Enphase: their engineering team is actively working on it, they requested that I provide my IP address as they had something they wanted to test. I will provide my IP when I get back home after work and share any further updates I get. (I’m based in NL with a KPN connection)
Hi Ron,
No. It was kind of dead. Didn’t response to anything anymore. No time to dive into this right now. I have a kitchen renovation. Ongoing. Need to finish it before the summer break. I’ll have to pass on Enphase installs for now.
Today, the API support replied to me.
…
We are also reviewing whether this behavior is related to the broader issue reported by other users across Europe, as you rightly pointed out.
…
They also asked for my IP addresses (GX and Envoy Gateway).
In my opinion, this could be a bug linked to a major update (such as the kernel) or a Modbus TCP server with unpatched security vulnerabilities. I suspect that for one of these two reasons, they were forced to switch Modbus TCP servers, necessitating unplanned development and validation work.
The second option seems more plausible to me; it would explain why no warning was issued and why the system wasn’t kept running—even by rolling back the firmware—while awaiting a fix.
Hello,
Today, Modbus TCP access was finally enabled after I was asked to provide the IP address of my Cerbo GX. However, the system now displays all three phases (L1, L2, and L3), even though my installation is single-phase.
After raising this with Enphase, I received the following response:
“We have reviewed your observation and would like to clarify that the fact that L1, L2, and L3 are now displayed does not mean that the system has been configured as three-phase. This is a change introduced in the latest software versions. Previously, single-phase installations only displayed L1, whereas the interface now also shows L2 and L3, even though they remain at 0 W, as shown in the screenshot you provided. This is simply a change in the way the information is presented and does not reflect any change in the electrical configuration of the system.”
To be honest, I find the handling of this issue quite disappointing. It took almost a month to enable a feature that already existed, and the end result is confusing because the way the data is presented has been changed without any prior explanation.
It gives the impression that this solution was implemented rather hastily. Displaying three phases for a single-phase installation, even if two of them permanently show 0 W, provides no practical benefit and is likely to confuse both end users and system integrators. It would have been far more sensible to keep the previous display for single-phase systems or, at the very least, clearly document this change.
Just for info, off the phone with Enphase, they added the internal IP of my Cerbo and now I have connection again. Also, for 3 phases while I have a 1 phase system but it’s visible again, so I’m good. They advised ppl to give them a call as the different systems require different solutions.
Installers should be allowed to setup modbus support. Without having to contact Enphase support. It is really odd that we need to contact them. The stories I read here are different…every single time. Ridiculous IMHO.
Every other inverter with modbus supports works, except Enphase. Yet they tell you to check the firewall settings. Right 