A remote diagnostic identifies the root cause of most solar and battery faults — often within 30 minutes. All major brands supported. You get a written report with the fault, the fix, and a cost estimate.
Book your free remote diagnosticHow diagnostics workSTS installed/commissioned an extra Givenergy battery for me. Communication was great and the engineer did a great job and even tidied up the existing wiring which made it look a great deal nicer than it did. Very happy so far and grateful to the team for their professionalism.
Fantastic support. We have a Givenergy system where one of our batteries was not working. Ronald successfully helped us get it back up. His perseverance was amazing….and it shows what REAL customer service means. Can’t thank you enough Ron!
Called spoke to Ron. Was very informative and more importantly listen to the issues regarding my system. Was very professional and tackled the problem and had my system back on it's way. Thank you once again Ron
Thank you for your diligence. On this occasion the battery was able to be saved but they have given a route to hopefully arrange a repair from the manufacturer.
This is the second time I have used Solar tech first time a faulty Givenergy inverter, tried all sorts to get it going my last call was to Solar tech and yes they got me back up and running, today system went down again due to a firmeware update and Ron talked me through everything all whilst he was on someone’s roof sorting their system out. I would recommend this chap to every body that has problems with their system no matter what make..
Ron is a super star. Two months ago my GivEnergy battery failed a firmware upgrade leaving it a brick. My installer couldn't/wouldn't fix it. GivEnergy couldn't/wouldn't fix it. Then they went into administration and all hope was lost. A flurry of emails later and Ron had diagnosed the fault (failed USB flash drive, something I'd suspected) and talked me through resolving it. Two months of nothing resolved in about 3 hours. It's great to work with someone who pays attention to the details, knows that they're doing (not just following a script) and gets stuff sorted without a fuss or up-charging.
Solar PV and battery storage systems are reliable, but they are also complex installations with hundreds of components and control points. Faults can develop over time for a variety of reasons — some are simple configuration errors that can be fixed remotely in minutes, others require physical inspection or component replacement on site. The good news is that most faults have a specific, identifiable cause. With the right diagnostic approach, you can understand what's wrong and decide on the best path forward.
At STS Solar Tech Support, we specialise in diagnosing solar and battery faults across all major brands. Whether your system uses GivEnergy, SolarEdge, Growatt, Sunsynk, Solis, Enphase, Huawei, Fox ESS, Fronius, Tesla Powerwall, or any of the many other inverter and battery brands available in the UK, we have the knowledge and tools to identify the root cause. We maintain detailed fault databases built from hundreds of real repair jobs, covering everything from firmware quirks to configuration best practices for every brand we support.
If you're not sure where to start, our remote solar diagnostic service is designed exactly for this — we analyse your system data, inverter logs, and setup to provide a full diagnosis without a site visit — the remote diagnostic is free, and remote fixes are a flat £125.
Your system has stopped generating, is producing less than expected, or has lost backup capability.
Panels and inverter installed but generating zero — or a figure that makes no sense.
See system not producing →Generating, but not as much as it should be. Output has dropped or never met expectations.
See system underperforming →Battery didn't switch to EPS or backup mode when the grid went down.
See no backup during power cut →Fault lights, display errors, or an inverter that won't start.
Battery not charging, not discharging, or showing communication errors.
Battery not charging from solar, the grid, or at all. Full diagnostic guide.
See battery not charging →CAN comms error, BMS fault, or battery not seen by inverter.
See battery communication fault →Battery charged but won't discharge or use stored energy when needed.
See battery not discharging →Portal offline, WiFi not connecting, or data not updating.
Portal showing offline, device unreachable, or data not updating.
See monitoring offline →Inverter or battery can't connect to your home WiFi network.
See WiFi not connecting →System shut down due to high grid voltage — causes, detection, and fixes.
See grid overvoltage →Installation or setup errors causing incorrect behaviour.
Export payment issues, tariff registration, and missing income.
No export payments arriving — SEG registration, metering, or supplier billing issue.
See not being paid for solar export →Smart Export Guarantee application stuck, rejected, or taking too long.
See SEG registration issues →Feed-in Tariff payments missing, late, or stopped after supplier change.
See FIT payments stopped →Post-installation issues, snagging, and workmanship concerns.
Faults specific to off-grid and island-mode systems — battery protection trips, charge failures, and generator interaction problems.
Battery protection trip cutting power — causes, SoC thresholds, and recovery steps.
See low voltage disconnect →Solar or generator not charging the battery in an off-grid setup — MPPT, charge controller, and configuration issues.
See off-grid system not charging →The problem sections above cover the main categories of faults. If you're not sure which one applies to your situation, use these starting points to narrow things down. If your system is producing nothing at all — no generation, no power, completely offline — start there. This covers total system failures, dead inverters, and zero-output scenarios.
If your system is generating but the output is consistently lower than you'd expect — especially if it has dropped over time or never reached the performance figures your installer quoted — check the system underperforming page. This covers partial faults, soiling, shading, and efficiency losses that don't stop generation entirely.
For battery-specific issues, if your battery isn't storing energy or the system won't charge it, go to battery not charging. If the battery is full but won't discharge or the system won't use the stored energy when you need it, check battery not discharging. Battery faults often stem from configuration settings rather than hardware failure, so these pages focus on the most common causes.
If you're seeing fault codes on your inverter display or in your monitoring app, the fault code itself is usually the fastest way to diagnose the issue. Check your brand's specific page — we have detailed fault code guides for GivEnergy, SolarEdge, Growatt, Sunsynk, Solis, and all other major brands. You can also browse the fault codes section to look up error codes across multiple brands.
If the fault is related to export payments — your system is generating and the grid is importing, but you're not receiving payment from your export tariff scheme — see our dedicated guide on not being paid for solar export. This usually comes down to export metering, tariff registration, or communication settings. A remote diagnostic can quickly determine whether the issue is technical or administrative.
Still not sure where to start? The best first step is a remote diagnostic. Tell us what you're seeing, share your monitoring data, and we'll pinpoint the problem in most cases without needing to visit your site.
Some solar faults are safe to investigate yourself with guidance — checking settings, restarting the system, or looking at logs. Others require professional intervention. Safety is our priority, so please call an engineer immediately if you see any of these signs:
Beyond safety-critical issues, consider calling a professional if DIY troubleshooting hasn't resolved the problem. If you've checked the obvious things — restart the inverter, check the WiFi, review the settings — and the fault persists, a remote diagnostic can identify the cause, unless it's the WiFi. WiFi isn't remote work: if a dongle or logger still won't reconnect after our WiFi not connecting guide, we can set it up on site, from £195. If the system has been offline or non-functional for more than a week, don't let it linger — the sooner you diagnose, the sooner you can get back to generating. If error codes keep reappearing after a reset, that's a signal that the underlying cause needs professional attention, not repeated resets. We're here to help: contact us for urgent situations or book a diagnostic to get started.
The Solar Not Working page walks you through the full triage process — inverter, battery, monitoring, and grid — in one place. Most people find their fault within two or three steps.
Describe what the system is doing — fault lights, generation figures, what the app shows — and we’ll identify the root cause. Most faults are diagnosed remotely in 30 minutes.
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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