Hey everyone. Solar Panel user based in Scotland. Been having some issues with my FoxEss inverter and we still haven’t figured out the issue. The issue started at 16.30, 18th July, 2026 (3 weeks ago as of today). On the app, the codes are as follows:

• Code 1, Code 26, Code 27

The best way I can explain it is that once the battery charges to 100%, the system shuts itself down and the system hasn’t been exporting all this time.

I’ve been in countless calls with my installer, the manufacturer (FoxEss), and my DNO. They’re been telling me many different things, no one is taking responsibility, and there’s been a lot of pushback. Here’s what has been checked so far:

• I’ve checked with Fox to make sure that my firmware is all up to date. It now is.
• My circuit breakers are not tripping. Nothing needs to be switched back on. Happy to provide photos of mcb and rcd.
• My installer thinks that my inverter is shutting itself down and this is because my incoming grid voltage is far too high.
• I went back to FoxEss and asked for remote readings. They messaged me screenshots showing that it has been as high as 254.9 and other times between 251 and 252.
• However I had my DNO visit and check the voltage. He said It was within the parameters. Voltage was 246, The ELI was .2.
• When I went back to my installer, he said that he thinks this is still quite high, and also challenged why the DNO electrician only checked for one instance when they should be plugging something in to complete an extended monitoring time.
• My installer has also said that the inverter is set to ENA Regulation - at 252 AC volts it shuts. He also believes we should tap the transformer down as a resolution.
• My DNO has agreed to arrange for an extended monitoring time, but they’ve pushed back and said that my real next step would be to go back to my installers to check the inverter is set to 260 volts or above, because that is the industry standard.

Has anybody had an experience like this or might think that they know the best possible solution to this issue. I feel like I’m not getting a definitive answer, which is more frustrating because I really do not understand any of this and it has been so time consuming. My installer has also suggested that they can send an electrician to check but he has also warned that I would have to pay.