⭐⭐⭐⭐⭐ Absolutely Outstanding Service! My GivEnergy system had completely gone down, and unfortunately I was getting absolutely no support from either the original fitter or the supplier. I was left completely stuck with a system that wasn’t working. I contacted Solar Tech Support and they were absolutely brilliant from start to finish. They quickly got to the bottom of the problem, knew exactly what they were doing, and managed to get my entire system back up and running. Hands down, these guys are absolute experts in their field. The level of knowledge, professionalism and customer service was exceptional, especially when I’d already been left without any support elsewhere. If you have a GivEnergy system and you’re struggling with an issue, don’t hesitate to contact Solar Tech Support. I honestly can’t recommend them highly enough. 5 stars all day long! 🌟🌟🌟🌟🌟
Fox ESS offline in Fox Cloud: the app, the dongle or the system?
- FoxCloud 2.0 app and web portal
- The step-by-step guide is free to follow
- Not affiliated with or endorsed by Fox ESS
You can re-pair a WiFi dongle yourself with the steps below. If it still won't connect, we set it up on site, from £195: we connect it to your WiFi, set up your router, including a separate 2.4 GHz network if it needs one, and check it's reporting. For an app or account problem rather than the WiFi, tell us what the Fox Cloud app and foxesscloud.com each show and what the inverter's own screen says: the remote diagnostic is free.
Book on-site WiFi setupFox ESS hubIndependent, not affiliated with or endorsed by Fox ESS.
I left an enquiry few days ago and got a call back today from Ron. I have FoxESS battery and inverter that seemed not doing the right job and after only few questions, Ron told me exactly what I need to do to restart my system, without even seeing it. After almost 2 weeks of not being able to use my FoxESS equipment, today is finally up and running. Very professional and knowledgeable. Thanks Ron
What an absolute star. Ron went well beyond what i would have hoped for. His attention to detail was incredible, even making good the work of others.
I sent a message on their website regarding a problem I have on my Givenergy system. Although not supplied by Ronald, I thought it was worth an email. Within the hour on a Saturday, he phoned and we discussed the problem. He logged in remotely and gave excellent advice. I'm too far away for his on-site help but he did diagnose the problem and was happy also to chat through my thoughts about an upcoming solar/battery install I'm planning. Great bloke.... if only he was nearer!
Givenergy panels and battery had been offline for a couple of months after various changes by Givenergy to their app etc. Ron did a fantastic job of sorting it out - got things up and running almost immediately, followed by some fine tuning to get things fully configured. What a legend - great service, great comms, great result.
I received a prompt response and excellent technical support for the remote diagnosis (Oxfordshire) and resolution of my GivEnergy EMS configuration. My GivEnergy issue involved a single inverter and battery that had a loss of calibration, a critical low voltage drop. It needed a recovery and re-calibration, and was supported via email into yesterday evening being resolved within 24 hours. Ron demonstrated a very high level of knowledge and experience in the intricacies of a GivEnergy EMS configuration, even surpassing the understanding of GivEnergy itself when it was still operational. I have already recommended their services to a neighbour as I’d be happy to use their services again based on the fair pricing and the quality of their support.
What's offline: the app, the datalogger or the system?
"Offline" means your system's datalogger has lost its internet link. The system usually keeps running, but offline doesn't prove it, so check the inverter's own screen. Work out which of these you have before you change anything.
The inverter itself
Look at the inverter's own screen first. On the H1(G2) the screen shows the fault message, and the inverter's green light means normal and its red light means a fault. In the FoxCloud 2.0 app, the plant list sorts systems into Normal, Faulty and Offline, and a plant's alarms sit under the bell icon at the top right, in Current and History lists. While the system is offline the app can't get new data from it, alarms included, so an empty alarm list proves nothing. If there's an alarm, look it up on our Fox ESS fault code index before you start on the WiFi. For Ground Fault or Iso Fault, see our Fox ESS ground fault guide.
Only the battery
A moderator on Fox's Tech Hub forum said in July 2025 that the web portal doesn't show the battery, so check it in the app. Owners reported the battery showing offline while the inverter kept working during Fox's app service disruption of 11 March 2026. If the inverter's screen shows BMS Lost or Bms Ext Fault, Fox's H1(G2) manual says communication with the battery has been interrupted: see our Fox ESS BMS communication fault guide.
Only the app
If foxesscloud.com shows current data but the FoxCloud 2.0 app doesn't, the problem is in the app: start at step 1.
The app, the portal and the datalogger
If neither shows current data, the next checks are your broadband router and then re-pairing the WiFi dongle: start at step 2. Fox's 2.0 app manual doesn't define messages such as "network unavailable", so treat them the same way.
Fox's own service
If foxesscloud.com won't load at all, the problem may be on Fox's side: Fox's notice of 11 March 2026 said its app service was restored on 12 March.
Fox's own checks, in order
Work through these steps in order. They follow Fox's own order for a system that shows no data: foxesscloud.com and the app first, then your broadband router, then re-pairing the WiFi dongle.
Sign in at foxesscloud.com in a web browser, with the same login as the Fox Cloud app. If the portal shows current data but the app doesn't, the problem is in the app: Fox's advice is to clear the app's cache or reinstall it. A VPN on your phone can also stop system data showing, so switch it off or use a UK server. A moderator on Fox's Tech Hub forum said in July 2025 that the web portal doesn't show the battery, so check the battery in the app. If foxesscloud.com itself won't load, the problem may be on Fox's side, and Fox normally puts its own outages right.
If foxesscloud.com shows no current data either, Fox's next step is to power-cycle your broadband router: switch it off, then back on. When it has reconnected, check foxesscloud.com again before you go on.
Fox says a WiFi drop is very rarely a fault in the device itself and is usually a change on your home network, such as a new router, a new WiFi password or new broadband equipment. Fox's WiFi dataloggers use 2.4 GHz, and Fox says some UK broadband routers arrive with 2.4 GHz switched off, so check your router's 2.4 GHz band is on. If anything has changed, the dongle needs re-pairing to your network as it is now. A LAN or 4G datalogger has nothing to re-pair: Fox says one that loses contact needs investigating, so go to step 7.
Read this step through first, because your phone will be off your home WiFi and mobile data while you do it. Our advice is the manual method first, because it's more reliable than the app. Fox's own manual starts with the app, so that route is the next step, as the alternative. Turn your phone's mobile data off, tell it to forget your home WiFi for now, make sure the router's 2.4 GHz band is on, and stay close to the dongle. Join the network named W- followed by the last seven characters of the dongle's serial number, with the password mtmt2020. Open 192.168.1.1 in a browser. A newer datalogger may need https://192.168.1.1/ typed exactly, with the slash at the end. If it asks for a login, try mtmt2020, then 12345678. These are Fox's printed defaults and may have been changed, so a second-hand system may refuse both. A newer datalogger asks you to change the password at first login, and that also changes its network password, so note it down. Choose your home 2.4 GHz network, enter its password and press Save. Allow a few minutes for it to show as connected.
In the FoxCloud 2.0 app, go to Me > WLAN Configuration, select your device, tap Connect Network, choose your WiFi, then Next and Finish. Fox's newer WiLAN dataloggers pair over Bluetooth, and on an iPhone the app needs permission to use Bluetooth.
If your phone can't find the dongle by Bluetooth or on its own WiFi network, stay close to it with mobile data off and try once more. Don't take the dongle out of the inverter: Fox's H1(G2) manual leaves the inverter's connections, its WiFi/4G port included, to authorised people, so this is a job for your installer or an engineer. Book on-site WiFi setup or ask your installer.
If the dongle won't pair or keeps dropping out after re-pairing, we can set it up on site, from £195. If the signal doesn't reach, a WiFi extender is an extra £75, and we carry them with us. If you have a LAN or 4G datalogger that has lost contact, Fox says it needs investigating, so contact STS for a remote diagnostic or ask your installer. If the inverter is a long way from the router, the answer on Fox's Tech Hub forum is a LAN or 4G datalogger, which your installer or an engineer fits, because Fox's manual leaves the inverter's connections to authorised people. Our guide to inverters that won't connect to WiFi covers getting a signal to the inverter. In the Fox Cloud app, Fox's own support request is under Me > Contact Us.
What "offline" means, and which datalogger you have
Fox Cloud is Fox ESS's monitoring service: the FoxCloud 2.0 app and the web portal at foxesscloud.com, which uses the same login. Fox's older app was called Fox ESS Cloud. Offline means the datalogger has no internet link. The system usually keeps running, but it can't be monitored or controlled remotely, so settings changes from the app won't go through until it reconnects. Fox Cloud's data come in 5-minute snapshots, and its energy-flow screen refreshes every 3 to 5 minutes, or every 5 seconds on selected devices with the minimum firmware.
Fox ESS UK's current inverter warranty policy (version 3.0, 3 November 2026) expects the inverters it covers to be connected to Fox ESS Cloud within 120 days of installation and kept connected, or the warranty period is shorter. A temporary loss caused by a product fault, the cloud, or something outside your or your installer's control doesn't count, as long as reasonable efforts are made to restore it. An older installation may be under an earlier policy, so ask your installer which one applies. See our Fox ESS warranty page.
Your system reaches Fox Cloud through a datalogger. It can be a plug-in stick, which on the H1, H1(G2) and KH fits the WiFi/LAN/4G port at the bottom of the inverter: a WiFi dongle, a LAN stick with a network cable to your router, or a 4G stick. Some models have it built in: Fox ESS UK's H1-G2 and KH pages list integrated WiFi and LAN (Fox's global site and Tech Hub call these the H1-G2-WL and KH-WL), and the H3 Smart has built-in WiFi with no plug-in dongle. Fox's compatibility table tells dataloggers apart by the first characters of their serial number: for example 9W2 is a Smart WiFi, 9L3 and 9L4 are Smart LAN, 9E4 and 9E5 are Smart 4G, and 9WL, 9WW and 9WX are the WLan-WW, which does WiFi and LAN.
A WiFi datalogger is re-paired when your network changes. Fox says a LAN or 4G datalogger that loses contact needs investigating instead. Where WiFi can't reach the inverter, the answer on Fox's Tech Hub forum is a LAN or 4G datalogger, which your installer or an engineer fits, because Fox's manual leaves the inverter's connections to authorised people. Fox's Smart LAN quick guide and its Smart 4G datasheet are on our Fox ESS documents page.
If someone else holds the Fox Cloud account, such as your installer or a previous owner, Fox's route is to email Fox ESS UK's service team with the datalogger's serial number. We cover all Fox ESS models: with your permission you can share your login with us, or we can arrange a monitoring account transfer for £95.
What the lights on your datalogger mean
Fox prints this table for its Smart WiFi 5.0 and WLan-WW dataloggers.
| Light | What Fox says it means |
|---|---|
| Red, flash every 0.1 seconds | Not connected to the router |
| Red, flash every 0.5 seconds | Has an IP address but hasn't connected to Fox's server |
| Red, flash every second | Connected to Fox's server |
| Green, one flash | Received a packet of inverter data |
We've found no Fox table for other dataloggers such as the Smart LAN and Smart 4G, and one reply on Fox's Tech Hub forum gave a red flash every two seconds for connected. The surer check is foxesscloud.com: if it shows current data, the datalogger is getting through.
The lights on the inverter itself are different: green means normal and red means a fault. The blue light means network on the H1-G2-WL, H3 Smart and EVO, but battery on the H1(G2) and KH.
Fox ESS error 40004 on the app login screen
If a five-digit number appears when you sign in to the Fox Cloud app, tell it apart from an inverter fault before you start re-pairing anything.
40004 isn't in Fox's inverter alarm lists
Fox's manuals for the H1(G2), H3 and KH list alarms by name, such as Grid Lost Fault, Iso Fault, Res Cur Fault and Pv Volt Fault, and the H3-Plus/P3-Plus manual adds four-digit codes. Fox Cloud's alarm history prints short numbers, such as Grid Voltage Fault (26). None of these is 40004, and we've found nothing from Fox ESS that explains it. For an alarm on the inverter's own screen, see our Fox ESS fault code index.
What one owner reported
One owner's post on FoxESS Community, an independent owners' and installers' forum, describes 40004 at the app's sign-in in June 2026, on app version V2.2.16. The web portal at foxesscloud.com and the inverter were both working normally. Clearing the app's cache and reinstalling it didn't help, but changing the app's region and language to Europe and English let the owner sign in, and switching back to German brought 40004 back. That's one owner's workaround, not a fix from Fox.
The check that tells you whether to worry
Open foxesscloud.com in a browser and sign in with the same account. If it shows current data, the problem is in the app: Fox's general advice for an app that isn't updating is to clear its cache or reinstall it, and to switch off any VPN. If the portal shows no current data either, work through the steps above from step 2. The system usually keeps running while it's offline, so if you're unsure, look at the inverter's own screen. If re-pairing the WiFi dongle doesn't bring it back, we can set it up on site, from £195: book on-site WiFi setup.
Questions about Fox Cloud connectivity
Get help if your Fox ESS system is still offline in Fox Cloud
Tell us what the Fox Cloud app and foxesscloud.com show, what the inverter's own screen says, which datalogger you have if you know, and whether your router has changed. If the dongle needs reconnecting to your WiFi, we can set it up on site, from £195. We cover all Fox ESS models, and for an app or account problem, with your permission we work through your login or an account transfer. Independent from Fox ESS and your installer.
- Not affiliated with or endorsed by Fox ESS
- No fix, no fee covers remote fixes. On-site work is quoted in writing before we start.
- On-site WiFi setup, from £195
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