Ron made more sense in 20 mins than our installer has done over the last 12 months There is a jungle out there and you need someone like Ron to give a comprehensive overview and solution
David · May 2026
Problem diagnosis · Fronius
Fronius Solar.web Offline — Not Updating or Connecting
Your Fronius Solar.web portal shows the system as offline or the monitoring data has stopped updating. In almost every case, this is a WiFi connectivity issue — not a fault with the inverter itself. Your system is still generating power while you troubleshoot.
Free remote diagnostic · pay only if we fix it — from £75 if remediable remotely
- Not affiliated with Fronius
- No fix, no fee
- WiFi + Datamanager troubleshooting
Solar.web been offline for weeks?
If basic troubleshooting has not restored your monitoring, the Datamanager card inside the inverter may have failed — or a firmware issue is preventing reconnection. We can diagnose the cause remotely and arrange a fix.
Book your free remote diagnosticBack to Fronius hubIndependent — not affiliated with Fronius International.
Big thanks to Ron. He was incredibly patient and helpful over the phone, taking the time to walk myself and the installer through every troubleshooting step. Through lots of testing he figured out the issue was definitely a hardware issue, which allows us to consider our next steps. Support fees are clear and they operate a “no fix no fee” policy. It is rare to find that kind of honesty combined with dedicated phone support nowadays. I highly recommend Ron, if you need help with your solar system don’t hesitate to give him a call.
Steve M · Jun 2026 Google
Our SolarEdge PV system with LG batteries had its first hiccup after 8 years of hard work. The Inverter failed. Fortunately I found Solar-Tech-Support who diagnosed the problem very quickly, ordered a replacement unit and fitted it shortly after we received the unit from SolarEdge. Very thorough and professional approach. Thank you, a solid 5 star recommendation.
Les Bennett · Jun 2026 Google
STS were incredibly responsive and helpful In diagnosing an issue with my GivEnergy inverter. Although distance meant it was impractical for me to use them to fully solve the issue, I’m grateful for the help and detail they provided. Don is a real professional gent and a hero in my eyes.
Adam Miller · Jun 2026 Google
My 90-year-old father-in-law had a solar system installed nearly three years ago that never worked properly and kept tripping out. Neither the original installer nor GivEnergy could resolve the issues, and we were even pushed towards replacing the system entirely when GivEnergy went bust. I contacted Ron at Solar Tech Support via WhatsApp, and within a few hours he had diagnosed multiple faults — including incorrect wiring that posed a potential fire risk. He carried out a home visit in Nottingham for £295 (including parts), fixed everything, completed firmware updates, and ensured the system was fully operational. Since then, it has worked perfectly. Ron was knowledgeable, responsive, and took the time to explain everything clearly. Highly recommended — excellent value and complete peace of mind.
Julian F · Jun 2026 Google
Ronald was great to help me sort out my giv energy inverter issue since company has gone bankrupt in april 26.
Ankur Kr. Gupta · Jun 2026 Google
Your system is still generating. Solar.web offline means the monitoring connection has dropped — it does not affect the inverter output. Your panels are still producing power and exporting to the grid normally. Only the remote monitoring link needs restoring.
Diagnostics
6-step Solar.web reconnection guide
Work through these steps in order. Most Solar.web connectivity issues are resolved by step 3 or 4.
1
Confirm the inverter is still generating
Check the inverter display. If the green LED is on and the screen shows current power output in watts, the system is generating normally. Solar.web offline is purely a monitoring issue — the inverter produces power independently of the internet connection.
This is important because it means there is no urgency. Your system is not losing generation while you work through the connectivity troubleshooting. If the inverter display is off or showing a red LED, that is a different issue — check the state code alarm guide instead.
2
Check your WiFi network is on 2.4 GHz
The Fronius Datamanager only supports 2.4 GHz WiFi. It cannot connect to 5 GHz networks. This is the single most common cause of Solar.web going offline in the UK — modern routers from Sky, BT, Virgin, and other ISPs often default to dual-band with automatic band-switching.
If your ISP recently upgraded your router, changed your broadband package, or you switched to a mesh WiFi system, the Datamanager may have lost its connection. Log into your router settings and confirm that a 2.4 GHz network is available.
Mesh WiFi systems (Eero, Orbi, Deco) are a frequent cause of Fronius disconnections. The Datamanager can struggle with roaming between mesh nodes. If you use mesh WiFi, try locking the inverter to a specific access point or using a separate 2.4 GHz access point with an Ethernet backhaul.
3
Power cycle the inverter
A power cycle resolves the majority of temporary Solar.web disconnections:
1. Switch off the AC isolator at the consumer unit
2. Switch off the DC isolator below the inverter
3. Wait 30 seconds
4. Switch the DC isolator back on, then the AC isolator
5. Allow five minutes for the Datamanager to reconnect
Check Solar.web after five minutes. If the system appears online and data is updating, the issue was a temporary communication drop. If it remains offline, continue to step 4.
4
Connect to the Datamanager and re-run the setup wizard
The Datamanager broadcasts its own WiFi network for configuration. Look for a network called FRONIUS_240 followed by a serial number. Connect your phone or laptop to this network — the default password is 12345678.
Once connected, open a browser and navigate to 192.168.250.181. This opens the setup wizard. Select your home WiFi network from the list, enter your WiFi password, and save. The Datamanager will disconnect its own access point and connect to your home network.
If the FRONIUS_240 network does not appear after a power cycle, the Datamanager card may have failed — skip to step 6.
5
Check for Datamanager firmware updates
Outdated Datamanager firmware can cause persistent connectivity issues, particularly after Fronius updates the Solar.web platform. If you can access the Datamanager web interface at 192.168.250.181, check the current firmware version under the system information section.
Fronius periodically releases firmware updates that fix connectivity bugs and improve WiFi stability. However, firmware versions cannot be skipped — if your unit is running a very old version, it may need intermediate updates before reaching the current release. If you are unsure about the update path, leave this step to an engineer.
6
Book a diagnostic if the Datamanager has failed
If the FRONIUS_240 WiFi network does not appear at all after a power cycle, the Datamanager card has likely failed. This is a hardware component inside the inverter that cannot be repaired — only replaced. Other signs of Datamanager failure include no LED activity on the card and the configuration addresses being completely unreachable.
STS can confirm remotely whether the issue is WiFi configuration or a failed Datamanager card, and arrange a replacement if needed. The inverter continues generating normally without the Datamanager — only monitoring is affected.
Why UK router changes are the top cause of Solar.web disconnections
The Fronius Datamanager was designed when 2.4 GHz WiFi was the standard. UK broadband providers have since moved to dual-band and tri-band routers, and fibre rollout across the country means millions of households have had their router replaced in the last two years. Each time a router is swapped, the WiFi network name or password may change — and even if they stay the same, the new router may handle the 2.4 GHz band differently.
Sky Q and Sky Glass routers, BT Smart Hub 2, and Virgin Media Hub 5 all use combined SSIDs that broadcast 2.4 GHz and 5 GHz on the same network name. The router decides which band to assign each device to, and the Fronius Datamanager sometimes gets pushed to 5 GHz where it cannot connect. The fix is either to create a separate 2.4 GHz SSID in the router settings or to use a dedicated 2.4 GHz access point for the inverter.
Mesh WiFi systems add another layer of complexity. The Datamanager connects to whichever mesh node has the strongest signal, but when that node hands off to another, the connection can drop. For reliable Fronius monitoring on a mesh network, the best approach is a separate 2.4 GHz access point connected via Ethernet to the mesh — keeping the inverter on a stable, non-roaming connection.
Solar.web offline — common questions
The most common cause is a WiFi connectivity issue between the Fronius Datamanager and your home router. This can be triggered by an ISP router upgrade, a WiFi password change, the router switching to 5 GHz only, or a temporary signal dropout. Mesh WiFi systems are also a frequent cause. Less commonly, the Datamanager card inside the inverter has failed. Solar.web offline does not mean your system has stopped generating — the inverter produces power independently of the monitoring connection.
The inverter continues to record generation data locally while the monitoring connection is down. When the connection is restored, the Datamanager syncs the buffered data to Solar.web, so you do not lose your production history. However, if the connection is down for an extended period, the local buffer may fill up. Restoring connectivity promptly ensures a complete record. Your actual energy generation and grid export are not affected by the monitoring status.
In most cases, yes. Start with a power cycle — switch off the AC and DC isolators, wait 30 seconds, and switch them back on. If that does not work, connect to the FRONIUS_240 WiFi network, go to 192.168.250.181 in a browser, and re-enter your home WiFi credentials in the setup wizard. Make sure your WiFi is broadcasting on 2.4 GHz. If the FRONIUS_240 network does not appear at all after a power cycle, the Datamanager card may have failed and needs professional replacement.
The Datamanager is a communications card inside the Fronius inverter that handles the connection to Solar.web. It contains a WiFi module and an Ethernet port. On Primo and Symo inverters, it is either integrated or installed as a plug-in card. The Datamanager broadcasts its own WiFi access point for initial setup, then connects to your home network to send monitoring data to the Solar.web portal. If the card fails, the inverter continues to generate power — only remote monitoring is lost.
Connect to the FRONIUS_240 WiFi network broadcast by the Datamanager — the default password is 12345678. Open a browser and go to 192.168.250.181. This opens the setup wizard where you can select your home WiFi network and enter the password. If the FRONIUS_240 network is not visible, try a power cycle first — switch off both AC and DC isolators, wait 30 seconds, then restart. The access point should appear within two minutes of the inverter powering back on.
Book
Solar.web still offline? We can fix it remotely.
We diagnose whether the issue is WiFi configuration, firmware, or a failed Datamanager card — and get your monitoring back online without an unnecessary site visit.
- Not affiliated with Fronius
- No fix, no fee
- Datamanager replacement arranged if needed
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