My Givenergy system went offline, so I lost control of it. Ron from STS and Craig from Norfolk Solar were most helpful in diagnosing the problem by phone. Full marks for their patience and ability.
Tony Jackson · Jul 2026 Google
Troubleshooting hub · UK-specific · Every major brand My Solar System Isn't Working —
My Solar System Isn't Working —
Full Troubleshooting Guide
If your solar system has stopped producing, your battery isn't charging, your monitoring has gone dark, or your inverter is showing a fault — this page covers every common cause and what to do next. No jargon. No guesswork.
- Written from real diagnostic experience — not manufacturer PDFs
- Covers all major UK inverter and battery brands
- Free remote diagnostic if you need expert help — no fix, no fee
Not sure where to start?
Most solar faults are diagnosed remotely in a single session. Tell us what you're seeing and we'll work it out.
Book your free remote diagnosticSafety: do not open inverter or battery enclosures. If you smell burning or see arcing, isolate at the consumer unit and call 999.
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
Very very helpfuland so quick. Made sure that a non expert like myself understood what the problem was and how to resolve it.
Declan S · Jun 2026
A really big thank you to Ron and his team, he has vast amounts of knowledge and got my system back up and running, also good to get on with. I was absolutely lost as to know what to do, no help from installer and somehow came across Ron and am I glad I did. I would definitely definitely recommend him to anyone who has faults with there solar system, any make I would say. Thanks again Ron a pleasure meeting you.
D R · Jun 2026 Google
I can’t praise this firm enough. After hearing my solar panels rattling in very windy conditions, I contacted Solar Tech (as my installers no longer trade). Ronald was fantastic at explaining what he thought the issue was likely to be. Communication was great throughout keeping me fully updated. The team worked really hard on the day to carry out the necessary work. I can now sleep soundly at night without worrying about the solar panels on my roof. I would thoroughly recommend this firm. Thank you for sorting the problem out.
Carolyn Addison · 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
Start Here
5 things to check before anything else
These five checks take under five minutes and rule out the most common causes. Do these before digging deeper.
1
Check your consumer unit for a tripped breaker or RCD
Look for the solar circuit — often labelled 'PV', 'Solar', or 'Inverter'. If a breaker is tripped (handle down or in the middle position), reset it. If it trips again immediately, stop and book a diagnostic — do not force it.
2
Check both isolator switches are in the ON position
There are typically two isolators: an AC isolator near the inverter and a DC isolator between the panels and inverter. Both must be ON. Visual check only — do not open any covers or touch internal components.
3
Note the exact fault code or display status on your inverter
Write down the exact text, number, or letter code shown. Different brands use completely different coding systems — a photo of the display is ideal. This single piece of information can identify the fault precisely.
4
Check if monitoring is offline vs system is actually not generating
These are two different problems. If your inverter display shows a current power output figure (e.g. "2.4 kW") but your app shows offline, you have a monitoring/comms fault, not a generation fault. The system is working — only the data link is broken.
5
Check whether the problem started after a specific event
A firmware update, a power cut, a router replacement, a stormy night, or a recently changed electricity tariff are all common triggers. The timing of a fault is often the fastest route to its cause.
Safety: Never open the inverter or battery enclosure. Never touch the DC cables from the solar panels — these carry live voltage even at night. If you smell burning, see arcing, or notice scorch marks anywhere in the system, isolate using the main consumer unit switch and call a qualified engineer immediately.
Inverter problems
Inverter
Inverter showing a fault or not turning on?
Inverter faults are the most common reason a solar system appears to have stopped working. Most show a code — the code is the starting point for diagnosis, not a cause for alarm.
Common
Inverter showing a red light
Red status light typically indicates a protection fault, grid issue, or hardware alarm. Each brand uses different flash patterns — the meaning varies significantly.
Inverter showing a red light Urgent
Inverter not turning on at all
No display, no lights, no response. Could be a tripped breaker, a failed internal fuse, or a hardware fault. Requires systematic elimination before assuming hardware failure.
Inverter not turning on at all High Volume
System not generating any power
Inverter looks fine but output reads zero. Often a configuration issue — export limits, grid impedance, or CT clamp errors — rather than a hardware failure.
System not generating any power Common
System producing less than expected
Output lower than the MCS design estimate. Could be shading, a failed string, optimiser issue, or a misconfigured export limit capping generation.
System producing less than expected Look Up
Got a specific fault code?
Inverters display alphanumeric codes that identify specific fault conditions. Look up your brand's fault code index for the exact meaning and recommended action.
Browse fault codesHow solar inverters work
Understanding how your inverter converts DC from panels to AC grid power — and what can interrupt that process — makes every fault diagnosis faster.
Read guideBrand-specific inverter fault pages
Not sure which inverter fault you have?
Our remote diagnostic reviews your monitoring data and fault history to identify the exact issue. Free if we can't fix it.
Battery problems
Battery
Battery not charging, not discharging, or showing an alarm?
Battery faults are the fastest-growing category of solar support calls in the UK. Many trace back to configuration errors made at installation — not hardware failure. The most common single cause is a CT clamp installed backwards.
Most Common
Battery not charging
Battery stays empty despite solar being available or cheap-rate tariff being active. Charge window settings, CT clamp orientation, BMS fault, or firmware mismatch are the typical culprits.
Battery not charging Common
Battery not discharging
Battery is full but not supplying the house. Discharge schedule, grid settings, minimum SoC threshold, or a CT clamp reading the wrong circuit are typical causes.
Battery not discharging Technical
Battery communication fault
Inverter has lost communication with the battery — shows as a comms error code. Common after firmware updates, power interruptions, or on new systems with mismatched firmware versions.
Battery communication fault Urgent
No backup power during a power cut
You have a battery but the house went dark during a grid outage. EPS must be explicitly enabled — it's off by default on most inverters. Also requires a dedicated EPS output circuit.
No backup power during a power cut Extremely Common
CT clamp installed wrong
A backwards CT clamp causes the inverter to misread the grid — resulting in battery charging when it should discharge, importing when exporting, or readings with the wrong sign. One of the most frequently missed installation errors.
CT clamp installed wrongHow battery storage works
Understanding BMS logic, SoC thresholds, charge rate limits, and dispatch scheduling makes it much easier to spot when something is wrong versus how the system is designed to behave.
Read guideBrand-specific battery fault pages
Battery behaviour is hard to diagnose without monitoring data
We review charge/discharge logs, CT clamp readings, and schedule settings to find the exact cause. Most battery faults are fixed remotely.
Monitoring & connectivity
Monitoring
Monitoring app offline or not updating?
A monitoring failure is not a generation failure. The two are completely separate systems. Every year, thousands of homeowners think their solar has stopped working — when it's only the data link that's broken. Check the inverter display directly before assuming the system has failed.
Very Common
Monitoring app gone offline
App shows no data or 'last updated X days ago'. Could be a local WiFi issue, a data logger hardware fault, a cloud-side outage, or a firmware update that broke the cloud connection.
Monitoring app gone offline Common
WiFi not connecting / logger offline
Most inverter loggers only support 2.4GHz networks. Changing your router, updating the WiFi password, or switching to a band-steering mesh system are the most common triggers.
WiFi not connecting / logger offlineHow solar monitoring works
Understanding the data logger → cloud → app chain makes it easy to pinpoint exactly where a monitoring failure has occurred and whether the system is still generating behind a broken data link.
Read guideBrand-specific monitoring & connectivity pages
Grid & export issues
Grid
Grid overvoltage, export limit problems, or system tripping on sunny days?
Grid-related faults are often the most frustrating because they're caused by infrastructure outside your property — not your solar system. But they still need to be diagnosed, documented, and escalated correctly to the DNO.
Grid Issue
Grid overvoltage — inverter reducing output
Inverter cuts output on sunny days because grid voltage exceeds 253V AC. This is required by law — the inverter is protecting the grid. Requires a DNO evidence pack to get fixed at the infrastructure level.
Grid overvoltage — inverter reducing output Common
Export limit set incorrectly
A misconfigured export limit caps generation at the wrong level, sometimes at zero. Can be set wrong at installation, reset by a firmware update, or misapplied when switching between G98 and G99 connections.
Export limit set incorrectly Financial
Not getting paid for solar export
SEG payments not arriving, FiT payments stopped, or export meter not registering generation. These are separate problems with separate fixes depending on which scheme applies to your installation.
Not getting paid for solar exportExport limitation explained
G98, G99, DNO agreements, and what a correctly configured export limit looks like.
Read guideG98 vs G99 explained
Grid connection standards, thresholds, notification requirements and compliance.
Read guideGrid overvoltage faults need a documented evidence pack
We build timestamped voltage logs and formal DNO complaint packs that get the issue escalated properly. Without this, DNO responses typically go nowhere.
By brand
Brand Support
Know your brand? Go direct to the right page.
Every major UK solar brand has a dedicated hub page covering its specific fault patterns, fault codes, configuration tasks, and diagnostic guides. Brand-specific advice is always more accurate than generic troubleshooting.
No production · optimiser comms · arc fault · red light
Open brand hub
Battery faults · portal offline · CAN fault · firmware
Open brand hub
Battery not charging · CT miswire · grid faults
Open brand hub
Error 04 · Error 117 · ShineWifi offline · isolation
Open brand hub
Grid overvoltage · no output · monitoring
Open brand hub
Dongle offline · Luna battery · no permission error
Open brand hubOther supported brands
Common questions about solar faults
The most common causes of a sudden stop are a tripped breaker on the solar circuit, an inverter fault triggered by a grid voltage spike, a power cut that left the inverter in a fault state, or a firmware update that introduced a bug. Check the consumer unit first, then the inverter display for fault codes. See inverter not turning on →
It means your system is generating fine but the data logger — the small device that sends readings to the cloud — has lost its internet connection. This is a monitoring fault, not a generation fault. Check your router is online and that the logger has power. Most logger reconnections are triggered by a simple power cycle of the logger unit. Full monitoring offline guide →
If it worked and then stopped, the most common triggers are: a firmware update that reset the charge schedule to defaults, a tariff change (e.g. switching to Octopus Intelligent) that requires different schedule settings, or a CT clamp that was marginal and finally failed. If your energy tariff or app changed recently, check the charge window settings first. Battery not charging guide →
Most solar faults are not immediately dangerous — they just stop the system working. However, certain situations require immediate action: if you smell burning near the inverter or battery, see scorch marks, notice a sparking sound, or observe arcing anywhere in the system, isolate from the consumer unit and call a qualified engineer. Do not investigate these yourself. For all other faults, a systematic remote diagnostic is the safe starting point.
The remote diagnostic is free — we only charge £95 if we fix your fault. It covers fault identification, a written action plan, and settings validation where possible. Most configuration faults — CT clamp errors, charge schedule issues, export limit misconfiguration — are resolved during the diagnostic session. On-site repairs start from £295. We always confirm the cost before starting any physical work. See full pricing →
Still not working? Let's diagnose it properly.
Tell us what you're seeing — fault codes, display behaviour, app status, when it started. We'll review your details and come back with a clear diagnosis path, usually same day.
- Free remote diagnostic · 30 minutes · no fix, no fee
- Written engineer summary included
- Independent — not affiliated with any installer or brand
We use cookies to measure traffic and improve our ads — including sharing limited, hashed details with Meta (Facebook) and Google to measure ad performance. Accept, or decline for essential cookies only. Privacy policy
STS Solar Tech Support
Usually replies within minutes
Hi there!
Got a solar fault or need a quick answer? Drop us a message — we usually reply within a few minutes. Mon–Fri, 9am–7pm.
Start WhatsApp Chat
Got a solar fault or need a quick answer? Drop us a message — we usually reply within a few minutes. Mon–Fri, 9am–7pm.
End-to-end encrypted