Inverter continually restarting and offline

Sunny65 · Tue Jan 06, 2026 7:20 pm

Yesterday my battery was playing up - charging at weird times. This evening my app has gone offline, it reports 0 on everything since 18.00 hours and when I went to have a look at it, the inverter seems to be going through a start up loop and making some clunky sounds.

Raised a ticket with foxess yesterday, and will reach out to support as it's a new system...

I could switch it off and back on again....

MaterialBarracuda48 · Tue Jan 06, 2026 7:28 pm

Did your installers leave you with startup/shutdown sequence?
And have you tried this already?

Sunny65 · Tue Jan 06, 2026 7:41 pm

I wish! The cowboys left me with nothing. But I have figured out how to turn it off from the fuse board.

MaterialBarracuda48 · Tue Jan 06, 2026 7:50 pm

Will has you covered

Your battery will have a silver button as seen on his video (for a different battery) but works same, hold until it clunks off the relay.

Note the Fox Cloud is very slow to update, you may have to wait 15 mins to see your system come back online.
The big clunks you hear are normal, usually takes 3-4 mins to self-test.

Sunny65 · Tue Jan 06, 2026 8:11 pm

Thank you. Have tried that. I'll wait and see what happens. Not the best of nights to be doing this ...

Sunny65 · Tue Jan 06, 2026 9:33 pm

Tried it twice and no joy. The inverter continues to say 'waiting, checking then stops and comes up with starting. The light on the dongle is red, not flashing.

Tue Jan 06, 2026 9:38 pm

The startup loop could be a number of things, if the grid power has become isolated the inverter will continually loop through waiting, checking and if no grid power is present it will fall back to waiting and then repeat a minute or 2 later.

If the inverter never starts up there will be no power to the datalogger which explains why it is showing as offline.

Or it could be the batteries are not providing sufficient power to the inverter - if the battery is very cold ( less than 2C) then it won’t provide the dc startup voltage the inverter needs, and leading up to that as the temperature drops you would have seen random charge events as the BMS attempts to warm them with maintenance charges (which is what you described).

If the batteries are extremely cold, they will effectively be in deep sleep and will recover once the temperature recovers - but when they are not available you will have to wait until there is sufficient solar power for the inverter to startup.

If the batteries are at normal temperature, check your grid supply, any circuit breakers or RCD’s that might have tripped.

Sunny65 · Wed Jan 07, 2026 3:07 pm

Thank you Dave.

The app is back online but the battery failed to charge last night and at the moment it's trying to discharge when it's below the system minimum. Battery now at around 10 degrees.

The battery did charge a little from the PV today....such a puzzle.

Would a firmware update help?

Wed Jan 07, 2026 3:23 pm

It wouldn’t have charged last night because the inverter didn’t have enough DC power to start up, that checking / waiting loop would have continued until this morning when the sun came up.

As the battery has warmed up a little it will be accepting charge from excess solar, but as it is hovering around minSoC it would be worth putting a little bit of charge in from grid now whilst it is warm (which would help warm it further), then hopefully it will be able to charge tonight when the temperature drops again.

MaterialBarracuda48 · Wed Jan 07, 2026 4:46 pm

Sunny65 wrote: ↑Wed Jan 07, 2026 3:07 pm Would a firmware update help?

If you EP5 is of the heated variety, then you must get a FW upgrade as it won't heat on 1.006, needs min v1.009 (latest is 1.011)

Do you see a WARM sticker on it?

Sunny65 · Wed Jan 07, 2026 4:52 pm

The app tells me it is heating. And yes, I checked and there was something on the battery that said it could heat up.

MaterialBarracuda48 · Wed Jan 07, 2026 4:56 pm

Sunny65 wrote: ↑Wed Jan 07, 2026 4:52 pm The app tells me it is heating. And yes, I checked and there was something on the battery that said it could heat up.

May as well get that FW done ASAP then, contact installer or email fox directly service.uk@fox-ess.com give your inverter SN and battery SN.

Sunny65 · Wed Jan 07, 2026 10:17 pm

Emailed Foxess a few days ago now but had no reply yet ..and have gone back to Eon as it was done by installers contracted by them ...so hopefully someone will sort it out.

It went down to -6 one night last week and it feels like it's been going on since then , so may have to build it an insulated box.

MaterialBarracuda48 · Wed Jan 07, 2026 11:07 pm

Sunny65 wrote: ↑Wed Jan 07, 2026 10:17 pm Emailed Foxess a few days ago now but had no reply yet ..and have gone back to Eon as it was done by installers contracted by them ...so hopefully someone will sort it out.

It went down to -6 one night last week and it feels like it's been going on since then , so may have to build it an insulated box.

Did you get a reply back from them looking like this for the subject?
service.uk@myfoxess.zohodesk.eu
[##99689##] Your ticket has been created

It could have gone to spam, but this is what you get back within a minute of emailing the address given above.

Sunny65 · Wed Jan 07, 2026 11:10 pm

yes - automated reply..how long do they usually take after that?

MaterialBarracuda48 · Wed Jan 07, 2026 11:18 pm

Sunny65 wrote: ↑Wed Jan 07, 2026 11:10 pm yes - automated reply..how long do they usually take after that?

1-2 Days, though it appears at the moment they are doing updates without sending a message.
So you need to check Fox Cloud 2.0 App again to see if FW was upgraded.

If not, send your battery number(s) off once again.
I have had to send 3 emails now, 1st one they update my Inverter only and didn't do the battery, 2nd email didn't get any results.

retsplines · Thu Jan 08, 2026 12:45 pm

I also experienced this weird behaviour today.

As soon as my system entered the configured "Grid allowed to warm up battery" time period, it started cycling through Checking... Waiting... constantly. I had to disable warm-up to get it to work again.

As a firmware engineer myself, I will say the quality of firmware/software seems incredibly poor on these things... Releases with no notes/changelog provided to even distributors or installers is concerning too.

Sunny65 · Fri Jan 09, 2026 9:02 am

Yes, the warm up function seems to impact mine too.

My battery got updated remotely and just got a message this morning from Foxess which said

"The firmware is already latest, I check the setting and found the import limit was set to be 25w, causing battery not charging, I have changed it to 15kW."

Which I definitely didn't set it to..as it's been working for months, but since Jan 1st the settings have just frequently changed from what's been scheduled and I have had the constant loop.

I'm not even sure I can access the part of the app he sent a screenshot of...

so now I have to wait and see if it works.

Bonus...I now have an email to reply to.

MaterialBarracuda48 · Fri Jan 09, 2026 9:21 am

Sunny65 wrote: ↑Fri Jan 09, 2026 9:02 am Yes, the warm up function seems to impact mine too.

My battery got updated remotely and just got a message this morning from Foxess which said

"The firmware is already latest, I check the setting and found the import limit was set to be 25w, causing battery not charging, I have changed it to 15kW."

Interesting that settings have changed like this, is your battery still on Version_BMS：1.006?

Fri Jan 09, 2026 9:25 am

There have been a few reports of this as a recent inverter firmware update on the G2’s introduced these power limits (under installer settings, also found at the inverter panel in Settings, on-grid, Export Control, ImportLimitPwr), the better news is that once set the inverter works perfectly again.

Sunny65 · Fri Jan 09, 2026 9:35 am

MaterialBarracuda48 wrote: ↑Fri Jan 09, 2026 9:21 am
Sunny65 wrote: ↑Fri Jan 09, 2026 9:02 am Yes, the warm up function seems to impact mine too.

My battery got updated remotely and just got a message this morning from Foxess which said

"The firmware is already latest, I check the setting and found the import limit was set to be 25w, causing battery not charging, I have changed it to 15kW."
Interesting that settings have changed like this, is your battery still on Version_BMS：1.006?

Battery now 1.011, No sun yet to see if it will charge and the battery warm up is trying to do it's thing.

MaterialBarracuda48 · Fri Jan 09, 2026 9:42 am

Good luck with the heating when needed then.

Sunny65 · Fri Jan 09, 2026 11:05 pm

Dave Foster wrote: ↑Fri Jan 09, 2026 9:25 am There have been a few reports of this as a recent inverter firmware update on the G2’s introduced these power limits (under installer settings, also found at the inverter panel in Settings, on-grid, Export Control, ImportLimitPwr), the better news is that once set the inverter works perfectly again.

I wish. Seems we are going round in circles. Now the inverter is offline and still looping and clunking. Messaged Foxess back.

Sat Jan 10, 2026 9:19 am

Sunny65 wrote: ↑Fri Jan 09, 2026 11:05 pm I wish. Seems we are going round in circles. Now the inverter is offline and still looping and clunking. Messaged Foxess back.

Sorry to hear that, do you have other high loads on overnight, such as an EV charger, heat pump, water heater or similar ?

Sunny65 · Sat Jan 10, 2026 9:51 am

Heat pump for the heating and water and sometimes the dishwasher because it's our cheap rate overnight - but these all take from the grid. But it usually manages to charge even with these on. At the moment not even one tiny bit.

This morning it seems to be charging from solar but only to 10% and then exporting to grid!!!

Checked max soc on inverter screen - says 100%

Just done another full reset.

And now it seems that the PV has stopped working, but may be a delay in the app