Skip to content
Brand support · Fronius

Fronius Inverter Support — State Codes, Isolation Faults & Aging Capacitors

One of the UK's most established string inverter brands — Primo and Symo units installed from 2012. State codes, isolation faults, grid disconnection, aging capacitors — we diagnose Fronius systems from Solar.web data and event logs. Remote-first. Independent from Fronius and your installer.
  • Not affiliated with Fronius
  • Primo, Symo & SnapINverter legacy
  • Capacitor replacement assessment
Not sure where to start?

State code error, isolation fault, Solar.web offline — we diagnose Fronius systems remotely in a single session.

Book your free remote diagnosticSee the Solar Health Plan

Safety: do not open inverter enclosures. If the inverter displays an isolation fault, do not repeatedly restart — this does not fix the fault.

5.0
13 Trustpilot reviews
Trustpilot Google

I have a GivEnergy system consisting of two batteries, two inverters and a controlling EMS (Energy Management System) which has not worked since Nov 2025. After six months I discovered Solar Tech Support, reached out to them and Ron phoned me back – how often do you get that service? Could not be more helpful – worked directly with me over the phone, outside what I would call normal working hours. Lucid explanations and we were able to discuss the issues and history using camera and email history. As this was a very rare setup, Ron was able to access an EMS expert in the field to confirm the solution. One sunny day in, I am now only paying for standing charge and a few pence for spikes in grid consumption while battery catches up with house demand.

Ian · May 2026 Trustpilot

When my GivEnergy system had an issue, I was completely left without support and had honestly lost all hope. Thankfully, I searched online and found Ron, which completely turned things around. After sending him a message, he responded incredibly fast and called me to assure me that he would get the problem fixed. I really admire his dedicated, supportive nature and his determination to find a solution. With this kind of outstanding attitude and customer service, he has absolutely secured a future customer in me.

Sree · May 2026 Trustpilot

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

Dennis Brown · May 2026 Trustpilot

Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)

Tony Deacon · May 2026 Trustpilot

Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone

Phill · May 2026 Trustpilot

I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues

michael fairhurst · May 2026 Trustpilot

Contacted Solar Tech Support in desperation. After explaining the issues I had with my system a diagnosis was made and a solution proposed. Fantastic service, even contacted a manufacturer to arrange replacement parts for me. Great communications, explained all they were doing and what I had to do, clearly and precisly. Followed up to confirm all was ok. Excellent service.

Mr Machin · May 2026 Trustpilot

After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.

Keith Ballard · Apr 2026 Trustpilot

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026 Trustpilot

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.

Christopher · Apr 2026 Trustpilot

I can add to the list of customers who had already 'given up' on GivEnergy due to their appalling customer service, and that was before they went into administration (their Trustpilot reviews don't lie!). So you can imagine my desperation when, having changed my ISP and my Inverter, predictably, proving to be the only device that didn't connect automatically to my new network, I found zero prospect of any customer support with GivEnergy having called in the administrators just five days earlier! The salvation came from Solar Tech Support. My IT advisor stumbled across their web site and some very helpful tips for beleaguered GivEnergy customers, as well as an offer to provide direct assistance. Nothing ventured, I decided to drop them an E-Mail, with very low expectations based on my experience of GivEnergy customer support. Within an hour Ron had responded with some pin point advice, and after a few exchanges of E-Mails he had nailed the problem, enabling the combined efforts of my IT advisor and solar installer to resolve it and reconnect my Inverter. Thank you Solar Tech Support, and Ron in particular, for coming to the aid of a deserted and despondent GivEnergy customer. Expert, razor sharp advice and first class customer service, even though I wasn't officially a customer.

customer · Apr 2026 Trustpilot

This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.

Andy Thomas · Apr 2026 Trustpilot

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!

Philip · Apr 2026 Trustpilot

I have a GivEnergy system consisting of two batteries, two inverters and a controlling EMS (Energy Management System) which has not worked since Nov 2025. After six months I discovered Solar Tech Support, reached out to them and Ron phoned me back – how often do you get that service? Could not be more helpful – worked directly with me over the phone, outside what I would call normal working hours. Lucid explanations and we were able to discuss the issues and history using camera and email history. As this was a very rare setup, Ron was able to access an EMS expert in the field to confirm the solution. One sunny day in, I am now only paying for standing charge and a few pence for spikes in grid consumption while battery catches up with house demand.

Ian · May 2026 Trustpilot

When my GivEnergy system had an issue, I was completely left without support and had honestly lost all hope. Thankfully, I searched online and found Ron, which completely turned things around. After sending him a message, he responded incredibly fast and called me to assure me that he would get the problem fixed. I really admire his dedicated, supportive nature and his determination to find a solution. With this kind of outstanding attitude and customer service, he has absolutely secured a future customer in me.

Sree · May 2026 Trustpilot

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

Dennis Brown · May 2026 Trustpilot

Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)

Tony Deacon · May 2026 Trustpilot

Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone

Phill · May 2026 Trustpilot

I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues

michael fairhurst · May 2026 Trustpilot

Contacted Solar Tech Support in desperation. After explaining the issues I had with my system a diagnosis was made and a solution proposed. Fantastic service, even contacted a manufacturer to arrange replacement parts for me. Great communications, explained all they were doing and what I had to do, clearly and precisly. Followed up to confirm all was ok. Excellent service.

Mr Machin · May 2026 Trustpilot

After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.

Keith Ballard · Apr 2026 Trustpilot

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026 Trustpilot

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.

Christopher · Apr 2026 Trustpilot

I can add to the list of customers who had already 'given up' on GivEnergy due to their appalling customer service, and that was before they went into administration (their Trustpilot reviews don't lie!). So you can imagine my desperation when, having changed my ISP and my Inverter, predictably, proving to be the only device that didn't connect automatically to my new network, I found zero prospect of any customer support with GivEnergy having called in the administrators just five days earlier! The salvation came from Solar Tech Support. My IT advisor stumbled across their web site and some very helpful tips for beleaguered GivEnergy customers, as well as an offer to provide direct assistance. Nothing ventured, I decided to drop them an E-Mail, with very low expectations based on my experience of GivEnergy customer support. Within an hour Ron had responded with some pin point advice, and after a few exchanges of E-Mails he had nailed the problem, enabling the combined efforts of my IT advisor and solar installer to resolve it and reconnect my Inverter. Thank you Solar Tech Support, and Ron in particular, for coming to the aid of a deserted and despondent GivEnergy customer. Expert, razor sharp advice and first class customer service, even though I wasn't officially a customer.

customer · Apr 2026 Trustpilot

This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.

Andy Thomas · Apr 2026 Trustpilot

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!

Philip · Apr 2026 Trustpilot
Fronius Faults

Common Fronius problems we diagnose

Every fault below has a proven diagnostic path. Click through for the specific page or book a diagnostic if you're unsure.

Inverter & Production
🔴
Alarm
State code alarm (xxx.yyy format)

Fronius displays state codes on the LED display and in Solar.web event log. Format xxx.yyy indicates fault category and specific event. Common codes: 102.x (grid fault), 401.x (isolation fault), temperature events. Diagnosis requires checking the exact code and timestamp.

See diagnostic guide →
🔆
Common
No solar production

Inverter powered but generating zero power. Could be a DC string fault, isolator not closed, or protection trip not cleared. Check Solar.web historical data and string-level metrics to identify the fault pattern.

See diagnostic guide →
📉
Performance
System underperforming

Inverter generating below expected output for conditions. May indicate soiled panels, partial string shading, or internal component degradation. Solar.web data analysis reveals the loss pattern over time.

See diagnostic guide →
Fault Codes

Fronius state code index

Seeing an error code in Solar.web or on the inverter display? Our full Fronius state code index explains what each code means, common causes, and safe next steps.

Fault code categories
·Grid & AC faults (1xx series) — voltage, frequency, phase
·Isolation & DC faults (4xx series) — earth isolation, string issues
·Temperature & hardware faults — thermal events, component failures
·Communication & monitoring errors — Datamanager, portal issues
Services

What we do for Fronius owners

Remote Fronius Diagnostic

We review Solar.web data, inverter settings, and fault history to identify the exact fault without a site visit.

State code root-cause analysis
Solar.web data review
Written engineer summary
Book remote diagnostic

Fronius System Recovery

Installer gone bust, Solar.web access lost, or monitoring never set up correctly? We recover access and rebuild documentation.

Solar.web access recovery
Datamanager reconfiguration
Warranty evidence pack
Start recovery

On-Site Fronius Repair

Isolation fault investigation, DC cable fault location, capacitor replacement assessment, component repair. Targeted visit — no guesswork on arrival.

Evidence-led targeted checks
Safety-focused report
Repair or replacement path
Discuss visit
Documents

Fronius datasheets, manuals & warranty PDFs

Download datasheets, installation manuals and warranty documents for Fronius Symo inverters and battery systems. Self-hosted and always current.

📄Product datasheets & specifications
📘Installation & commissioning manuals
🛡Warranty terms & coverage documents
📱App & software setup guides
🔌Wiring diagrams
Fault Codes

Fronius fault code index

Seeing an error code on your Fronius inverter? Our fault code index explains what each code means, common causes, and safe next steps.

·Battery communication & BMS faults
·Grid connection & frequency faults
·Over-temperature & protection events
·Solarweb monitoring & connectivity errors

About Fronius systems — what you need to know

Fronius is one of the UK's most established solar inverter manufacturers. The Primo (1–15kW single-phase) and Symo (3–25kW three-phase) ranges have been installed since 2012, making them some of the oldest string inverters still in widespread use. The legacy SnapINverter series (Galvo) from 2012–2018 is also still supported.

Fronius inverters are string inverters — no optimizers, whole-string MPPT. State codes (xxx.yyy format) are the standard fault language — the first three digits identify the fault category (102 for AC grid, 401 for isolation), decimal digits for specific events. Isolation faults are most serious — they indicate DC-to-earth resistance drop and trigger automatic shutdown for safety.

The Solar.web portal and app are powered by the Fronius Datamanager communication card. Many units from 2012–2018 are now 8–12 years old and approaching capacitor end-of-life. Capacitor degradation is the most common age-related failure causing intermittent shutdowns and output reduction. If you're searching for Fronius repair UK, Fronius state code, Fronius isolation fault, Fronius Solar.web offline, or Fronius capacitor replacement, STS provides independent diagnostic and repair support across the UK — not affiliated with Fronius.

We also support

STS supports all major inverter and battery brands — not just Fronius. If you have a mixed-brand system or are comparing options, visit the brand hub.

Browse all 19 brands
FAQ

Fronius questions answered

State codes appear on the inverter LED display or in Solar.web event log. Format xxx.yyy — first three digits identify fault category (102 = AC grid, 401 = isolation), decimal digits identify specific event. Find your code: in Solar.web go to Current Data > Inverter Status, or on inverter press button to scroll display. Note exact code and timestamp. See code decoder →
Isolation fault means inverter measured a drop in DC-to-earth resistance below safe threshold. Common causes: water ingress into MC4 connectors, cracked cable insulation from UV, or failed panel junction box. It's a genuine safety event — inverter shuts down to protect the grid. Do not repeatedly restart; this does not fix the fault and may make diagnosis harder. Isolate system and book an inspection.
If inverter is generating but Solar.web shows no data, the Fronius Datamanager communication card has lost internet connection. This happens after router changes, WiFi password updates, or broadband failures. Access Datamanager setup wizard by navigating to inverter's IP address on local network (found in router DHCP list), or use Fronius Solar.web app Bluetooth setup to reconnect.
Fronius SnapINverter (Galvo, Primo) units from 2012–2018 are now 6–12 years old. Capacitor degradation is most common age-related failure — causes intermittent shutdowns, output reduction, eventually complete failure. Capacitor replacement is viable and cost-effective on units less than around 10 years old if otherwise well-maintained. We assess repair-vs-replace decision remotely using Solar.web historical data.
Book

Ready to fix your Fronius system?

Tell us what's happening. We'll review your details and come back with a clear diagnosis path — usually same day.

  • Not affiliated with Fronius
  • Free remote diagnostic · no fix, no fee
  • On-site visits available across Yorkshire

By submitting you agree to be contacted about your diagnostic request. We don't share your data with 3rd parties.

Call 07944 877 329 Book free diagnostic