Smart Dongle LED flashing red, FusionSolar not updating after reconnection, or dongle hardware suspected failed? 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. We don't set up or diagnose WiFi remotely or over the phone: it's quicker and more reliable done on site. If the dongle LED is solid green but FusionSolar still shows no data, it's likely your FusionSolar account: the remote diagnostic is free, and a remote fix is £125, only if we fix it.
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Ron want out of is way to help, nothing was to much. He was very thorough in what he did Very knowledgeable I would highly recommend Ron and his company He did a fantastic job for me. if you have any problems, he'll do his best to help you out and resolve your problem. I wouldn't hesitate to recommend them
Excellent response to diagnose a problem on our SolarEdge installation. Kept us informed at every step. Diagnosis quickly completed and solution implemented.
⭐⭐⭐⭐⭐ 5-Star Review – Solar Tech Support Installing solar panels is only the first step! To get the best possible performance and maximise your investment, you need to make sure your system is configured correctly and all settings are properly optimised. **Solar Tech Support did exactly that for me, and I couldn't be happier with their professional service!** Their knowledge, expertise, and attention to detail helped me optimise my solar system to get the most out of it. If you already have solar panels and battery storage, I highly recommend contacting Solar Tech Support for professional advice, system optimisation, and technical support. Don't just install solar panels – make sure you're getting the maximum benefit from your investment! ⭐⭐⭐⭐⭐ Highly recommended! Thank you, Solar Tech Support, for your excellent service!
Solar Tech Support is an absolute lifesaver. My solar and battery system stopped working completely, but after one quick phone call, they fixed the problem straight away. The original provider, GivEnergy, has gone into administration, leaving me entirely without support from the original installers. It was a terrible situation on GivEnergy’s part, but thankfully, Solar Tech Support came to the rescue!
Ron was very knowledgeable and patient as we worked through the cause of Givenergy Hybrid Inverter suddenly failing (with 0W grid). He was able to quickly identify the probable cause, and point me in the right direction to identify the ‘burnt out’ AC isolator switch & piece of cable, which I was able to find a local electrician to replace. The best £95 I have spent. Thanks Ron.
Great experience with STS great communication from Ron, very helpful and knowledgable. Installed me a second Givenergy battery to help take the strain off my original 9.5 that needs refurb due to a weak cell. They secured me an 8.2 arranged install. Levi arrived the whole install was done within 1.5 hours - great tidy job. Worked with me to alter my setup to allow easy removal of my 9.5 when i can get it away for refurb - very happy with their service and its reassuring to know there is a company out there that can help look after my givenergy system
Most often it's only the monitoring link. When FusionSolar goes offline, the system usually keeps running, so check the inverter's own screen or status lights. The SUN2000 inverter and LUNA2000 battery (if fitted) don't need the Smart Dongle to run. What you lose is visibility: you cannot see generation data, battery status, or fault alerts until the Smart Dongle reconnects.
Start with a power cycle (step 3). If that doesn't work, reconnect the WiFi (step 4). If WiFi is unreliable at the inverter location, skip to the Ethernet fallback (step 6).
Check the indicator lights on the front of the SUN2000 inverter. If they're on and showing no alarm, the inverter is most likely running normally, and the offline issue is purely a monitoring connectivity problem.
Inverter is fine. Problem is the Smart Dongle connection to FusionSolar. Continue to step 2.
Inverter has a separate issue. Check for fault codes and see our AFCI fault or inverter not turning on guides.
The Smart Dongle (model SDongleA-05, also called the WLAN-FE) is a small module plugged into the USB port on the bottom of the SUN2000 inverter. Check its LED:
If the dongle is not physically present, it may have been removed or never installed. The inverter will generate without a dongle but cannot send data to FusionSolar.
A power cycle clears temporary communication faults and forces the dongle to re-establish its connection. Follow this exact sequence:
Wait 5 minutes, then check FusionSolar. If data reappears, the issue was a temporary communication fault.
You need to be physically near the inverter for this step. The FusionSolar app connects directly to the dongle's local WiFi network to reconfigure it.
The dongle supports 802.11b/g/n on 2.4GHz only (2.412–2.484 GHz). If your router uses a combined 2.4/5GHz network, the dongle may fail to connect. Create a separate 2.4GHz SSID or disable band steering. 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.
After reconnecting WiFi, stay in the Communication configuration screen:
This re-establishes the secure link between the Smart Dongle and the FusionSolar cloud. Wait 5–10 minutes, then check FusionSolar for live data. The dongle LED should turn solid green.
Data from the period the dongle was offline will be missing. If the inverter stored data locally during the outage, some historical data may backfill automatically — but this depends on the inverter model and firmware version.
The Smart Dongle WLAN-FE has a 10/100M Ethernet (RJ45) port as well as WiFi. If WiFi is unreliable at the inverter location — common in garages, lofts, or buildings with thick walls — Ethernet provides a permanent, stable alternative.
If running a cable to the router is impractical, a powerline adapter pair (e.g. TP-Link AV600) can bridge the gap using your home's mains wiring.
Huawei SUN2000 inverters use a Smart Dongle (SDongleA-05 WLAN-FE) to send generation, battery, and fault data to the FusionSolar cloud platform. The dongle connects to your home WiFi on the 2.4GHz band and maintains a persistent encrypted link to Huawei's servers. When you change your broadband provider, get a new router, or update your WiFi password, the stored credentials in the dongle no longer match and the connection drops. This is the single most common reason FusionSolar goes dark.
While the monitoring link is down, the system usually keeps running, so check the inverter's own screen or status lights. What you lose is visibility: you cannot see how much the system is generating, whether the battery is charging and discharging correctly, or whether any fault conditions have occurred. For homeowners on the Smart Export Guarantee (SEG) or time-of-use tariffs, monitoring data is also useful for verifying that battery dispatch and export schedules are working as configured.
If the steps above do not resolve the issue, the Smart Dongle hardware itself may have failed. Dongle failures are relatively uncommon but do occur, particularly after power surges or firmware update failures. If the dongle has failed, we tell you on the visit and quote the replacement first. Replacement dongles are available from Huawei solar distributors in the UK.
Smart Dongle LED still red, FusionSolar not updating, or dongle hardware suspected failed? 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. If the signal doesn't reach, a WiFi extender is an extra £75, and we carry them with us. If the dongle LED is solid green but FusionSolar still shows no data, it's likely your FusionSolar account: the remote diagnostic is free, and a remote fix is £125, only if we fix it.
Due to unprecedented demand we’re currently only carrying out on-site work in Yorkshire, and replies are taking up to 7 days. Remote diagnostics continue for the whole UK as normal.
Every message is read and answered, so please don’t send it twice; that only slows the queue.
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