Most Sunsynk configuration issues are fixed remotely in a single session. Tell us what you're seeing and we'll work it out.
Book your free remote diagnosticSafety: If your battery is showing error lights or unusual behaviour, isolate at the DC switch before investigating.
My issue was assessed and resolved quickly once the engineer was able to look at the problem. This took a little longer than I had expected (3 days) and keeping the PC on all day/everyday with Sentinel open was a little cumbersome I thought. That said, with little support coming from GivEnergy nowadays it was good to find someone who knew the platform and could resolve my issue.
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
I wholeheartedly recommend. Many thanks to Ron. Amazing. Everything is fixed. And I feel safer now that I know where to come for support if anything else happens. I contacted STS for help via their extremely useful website which told me exactly what I had done wrong to require support. My GivEnergy battery had been dead for a while and an attempted firmware update had stopped the inverter. The support was prompt and very professional and over and above what I expected. I was helped every step of the way with clear instructions and e-mail support for questions. The issue was resolved within 24 hours and a technical report produces from log data to share with Octopus to try to get to the bottom of how the original issue occurred. Despite Ron saying that mine was a familiar issue with Octopus Intelligent Flux, this to me was service over and above expectations.
We have a GivEnergy system, both GivEnergy and our installer have gone bust! Ron was able to remotely log in to our system and sort the issue within about 30mins. Would definitely recommend and will be using in future
Excellent service from Solar Tech Support. Extremely quick to respond, easy to deal with and clearly very talented engineers. They were persistent throughout a complex GivEnergy battery issue and resolved everything completely. Highly knowledgeable, professional and reassuring support from start to finish. Highly recommended.
Great advice from Ronald at Solar Tech Support, got my inverter back on line and stable.
Every fault below has a proven diagnostic path. Click through for the specific page or book a diagnostic if you're unsure.
Charge window set correctly in Solarman but battery stays at minimum SoC overnight. Often a TOU configuration error, grid charge disabled, or battery SoC minimum threshold too high. Very common after Octopus tariff changes.
See diagnostic guide →The Sunsynk inverter has native Octopus Agile, Intelligent, and Go integration but requires precise schedule configuration. Common issues: charge windows offset by BST/GMT, grid charge enable toggle, SoC target not set high enough. We configure the full schedule remotely.
See diagnostic guide →Battery not powering the house during peak times or grid outage. Could be a discharge schedule configuration error, SoC minimum threshold set too high, or an EPS/backup power circuit issue.
See diagnostic guide →Sunsynk hybrid inverter powered but not generating. Check Solarman for DC input voltage and error codes. Common causes: DC isolator tripped, string fault, or grid connection fault.
See diagnostic guide →Inverter trips off grid due to AC voltage or frequency exceeding G98/G99 limits. Common in areas with many solar systems on the same substation. Reconnects automatically but may need export limiting to prevent repeat trips.
See diagnostic guide →Sunsynk supports EPS (Emergency Power Supply) mode but it must be correctly wired and configured. If the house lost power during a grid outage despite a charged battery, EPS is likely disabled or the load circuit isn't connected to the EPS output.
See diagnostic guide →Solarman (formerly PVMaster) shows no data. Usually caused by the inverter's WiFi/4G datalogger losing connectivity. The system usually keeps running, but offline doesn't prove it, so check the inverter's own screen. Router changes, password updates, or logger hardware failure are the most common causes.
See diagnostic guide →No green LED, no red LED, nothing in the app. In most cases of a completely dark logger the dongle is fine and the 12V supply feeding it has failed on the board inside the inverter, the fault Sunsynk trace to capacitor C9. Your solar keeps generating throughout. Free checks first.
See diagnostic guide →Sunsynk dataloggers require 2.4GHz WiFi. Many 'monitoring not working' reports after router upgrades are caused by the new router defaulting to 5GHz or using band steering. Start with our general WiFi checks. 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.
See diagnostic guide →Sunsynk fault codes appear in the Solarman app and on the inverter display. Common codes relate to: grid voltage faults (F43 and F44), battery communication errors, DC bus faults, and temperature protection trips. Share your exact code when you book — we identify the root cause as part of the remote diagnostic. Solarman WiFi connectivity errors are the exception. We don't set up or diagnose WiFi remotely or over the phone: it's quicker and more reliable done on site.
We review Solarman data, TOU schedules, and error history to identify the exact fault without a site visit.
We configure your Sunsynk charge schedule from scratch for Octopus Agile, Intelligent, Go, or Flux. Most configuration faults are resolved in a single remote session.
EPS circuit verification, DC cable fault location, CT clamp correction, component replacement.
Download datasheets, installation manuals, warranty documents and app guides for Sunsynk hybrid inverters and ECCO batteries. Self-hosted and always current.
Sunsynk makes hybrid inverters that are particularly popular with UK installers for their flexibility and strong tariff integration. The inverter handles both solar generation and battery storage, with a built-in grid charger that allows the battery to be charged from the grid at cheap-rate times. Sunsynk integrates directly with Octopus Agile, Intelligent, and Go tariffs through configurable Time of Use (TOU) schedules — but this only works correctly when configured precisely. Many 'battery not charging' complaints are actually configuration errors, not hardware faults.
Monitoring is provided by the Solarman app (formerly PVMaster) and the SolarmanPro platform for installers. The inverter's WiFi or 4G datalogger must maintain a stable internet connection for remote data access. The most common searches we handle for Sunsynk: Sunsynk battery not charging, Sunsynk cheap rate not working, Sunsynk Solarman offline, Sunsynk grid disconnect, and Sunsynk Octopus configuration. STS provides independent Sunsynk support — not affiliated with Sunsynk Energy.
STS supports all major inverter and battery brands — not just Sunsynk. If you have a mixed-brand system or are comparing options, visit the brand hub.
Browse all brandsSunsynk fault code, or a battery ignoring its charge schedule? Most faults are settings, not hardware. Independent engineer, most fixed remotely.
See all problemsSolar monitoring portal showing offline? Tell a local WiFi fault from a dongle hardware failure, a firmware issue or a cloud-side outage, and fix it.
See Solarman offlineBattery didn't kick in during a power cut? EPS or backup mode may be off, the battery may have been too low, or the backup circuit may be wired wrong.
See no backup powerIndependent Sunsynk setup support across the UK — 1 setup procedure STS engineers explain step by step. Free remote diagnostic, no fix no fee.
See Sunsynk setup & how-to guidesEvery Sunsynk F code explained, including F56 DC_VoltLow_Fault and F14 DC_OverCurr_Fault. What each means, the cause, and whether we can fix it remotely.
See fault codesDownload Sunsynk datasheets, installation manuals, warranty PDFs, app guides and wiring diagrams. ECCO, Sunsynk hybrid inverters, and Hubble batteries.
See documents & downloadsTell us what's happening. We'll review your details and come back with a clear diagnosis path — usually same day.
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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