Power-One and ABB Aurora Inverter Repair and Fault Codes
A yellow or red light on your Aurora, a W or E code on the display, or no output at all? We diagnose and repair Power-One and ABB Aurora inverters from any installer, across England, Wales and southern Scotland, and replace them when they’ve reached the end of their life.
Repairs you can rely on
- MCS registered
- NAPIT registered
- TrustMark approved
- Fully insured
- Any installer’s system
- In-house engineers — no subcontractors
Call us on 0800 156 0191
Monday to Friday, 9:00am–5:00pm
Is this what you’re seeing?
A yellow light on the front of the inverter
The red GFI light on
“Missing Grid” or “Grid Fail” on the display
An E code such as E018 or E025
A green light that keeps flashing in good daylight
A blank screen in daylight
Zero output on a bright day
The solar breaker in the consumer unit keeps tripping
Write down the message and code on the display, and the model on the label on the side of the inverter, for example PVI-3.6-TL-OUTD.
Call 0800 156 0191 or use the fault finder further down this page. If the solar breaker keeps tripping, or the red light is on, leave the system switched off until an engineer has looked at it.
Common Aurora faults
Power-One made the Aurora inverters fitted to many UK homes in the feed-in tariff years. ABB took over the range, then sold its solar inverter business to FIMER, which completed in 2020. FIMER went through a restructuring and was bought by a McLaren Applied company in January 2025. Many Auroras are now more than ten years old, and most are outside their original warranty.
Earth and insulation faults
E018 means the inverter has detected leakage current to earth on the panel side. E025, “Riso Low”, means the insulation resistance of the panels and cables measured below 1 MΩ before the inverter connected. E018 lights the red GFI light. E025 shows the yellow alarm light, and the inverter won’t connect until it’s fixed. Common causes are water in a connector, a damaged cable or a failed panel, and finding them needs an insulation tester. See isolation and earth faults explained. See solar PV electrical testing for how it’s tested.
Grid faults
W003 “Grid Fail” and the related grid voltage and frequency warnings mean the grid is outside the limits the inverter is set to. A one-off usually clears itself. If it happens on sunny afternoons, or E036 “Vout Avg Error” appears, the local grid voltage may be running high, and that needs checking.
Faults inside the inverter
Codes shown as “Int. Error” on the display, along with E014 overheating that keeps coming back, point to a problem inside the inverter. On a unit this age, a repair isn’t always possible or worthwhile.
Repair or replace?
We always diagnose first. Earth faults and grid trips are usually outside the inverter. If the Aurora itself has failed, we replace it with a current model: a like-for-like string inverter, or a hybrid ready for a battery. You get a clear written quote before any work starts. Read more about inverter repair and replacement and how long solar inverters last.
Aurora error codes and what they mean
The codes below are from Power-One and ABB’s manuals for the Aurora UNO single-phase inverters (PVI-3.0, 3.6 and 4.2-TL-OUTD) fitted to most UK homes. Some other Aurora models use codes differently, so tell us your model as well as the code. Don’t open the inverter or disconnect its cables yourself.
| Code | What it means | What to do |
|---|---|---|
| Green light flashing | The inverter is starting up and checking the grid | Normal at dawn and dusk. If it flashes all day in good light, call us. |
| Yellow light | The inverter has detected a fault | Note the message and code on the display, then call us. |
| Red light (GFI) | A ground fault on the panel (DC) side | Call an engineer to test the panel wiring for earth faults. |
| W001 Sun Low | Not enough light, or the panel voltage is too low to start | Normal at dawn, dusk and on very dull days. If it shows in good light, call us. |
| W002 Input UV | Panel input voltage too low | As W001. If it persists in good light, call us. |
| W003 Grid Fail | Grid voltage or frequency outside the inverter’s limits | A one-off usually clears itself. If it keeps happening, call us to check the grid voltage at your property. |
| Missing Grid | The inverter can’t detect the grid | Check the solar breaker in the fuse board and the AC isolator are on. If they are, call us. |
| E001 Input OC / E002 Input OV | Panel input current or voltage above the inverter’s limit | Call an engineer to check how the panels are wired to the inverter. |
| E014 Over Temp | The inverter has got too hot | Keep the area around it clear and let it cool. If it comes back, call us. |
| E018 Ground Fault | Leakage current to earth detected on the DC side | Call an engineer. The cause, often water in a connector or a damaged cable, needs finding. |
| E025 Riso Low | Insulation resistance on the panel side below 1 MΩ before connecting | Call an engineer to test the panels and cables. |
| E023 DC Inj Error | Too much DC current on the AC output | Call an engineer. |
| E036 Vout Avg Error | Average grid voltage out of range, usually too high | Call us. We check the voltage and, if needed, help you raise it with the network operator. |
| Other “Int. Error” codes | A fault inside the inverter | Call an engineer. On an older Aurora, replacement is often the sensible fix. |
When to call an engineer
Call us if you see any of these:
- The red GFI light, or E018 or E025
- A yellow light that doesn’t clear
- W003 or E036 coming back on sunny days
- Any “Int. Error” code
- Any code that isn’t in the table
Not sure it’s the inverter? Our solar panels not working checklist covers the safe checks you can make first. Call 0800 156 0191 or use the fault finder below.
Why L&R Renewables
Any installer’s system
It doesn’t matter who fitted your Aurora inverter or whether they’re still trading.
Certified, in-house engineers
We’re MCS and NAPIT registered and TrustMark approved, and our own engineers carry out every job.
Honest about repair versus replacement
If a repair will do the job, that’s what we recommend.
England, Wales & southern Scotland
We cover England, Wales and southern Scotland.
Frequently asked questions
What does the yellow light on my Aurora inverter mean?
A yellow light means the inverter has detected a fault and stopped feeding power to your home. The display shows a message and a code, such as W003 Grid Fail or E018. Write both down and call us, because most codes behind a steady yellow light need an engineer.
What is Aurora error E018?
E018 means the inverter has detected leakage current to earth on the panel (DC) side, and the red GFI light comes on. It’s often caused by water in a connector, a damaged cable or a failed panel. Finding it needs an engineer with an insulation tester.
Can you still repair a Power-One or ABB Aurora?
Yes. We diagnose the whole system first, because many faults are in the wiring, isolators or connectors, not the inverter. If the inverter itself has failed, replacing it with a current model is usually the better fix on a unit this age. You get a clear written quote before any work starts.
Will replacing my Aurora affect my feed-in tariff?
No, as long as the system still meets the scheme rules. Ofgem allows you to repair or replace equipment. Tell your FIT supplier when the inverter is changed, and send meter readings as normal.
My installer has gone bust. Can you still help?
Yes. We don’t need the original installer to be involved, and we provide the certification and documentation for any new inverter we fit. See solar installer gone bust? for what else still protects you.
Related pages
Solar inverter repair
Repair and replacement for every major inverter brand.
Solar panel repair
Diagnosis and repair for the whole system, from any installer.
Solar panel servicing
An annual health check that catches faults early.
Other inverter makes we repair: SolarEdge, Fronius, SMA, Growatt, Solis, SolaX and Sofar. We work on any make, whoever fitted it. Replacing an old inverter? See our guide to hybrid inverters.
Tell us what your Aurora inverter is doing
Answer four quick questions — including the error code — and leave your details, and we’ll call you back to arrange a visit. Prefer to talk? Call 0800 156 0191, Monday to Friday, 9:00am–5:00pm.
Solar fault finder
What’s happening with your system?
What make is your inverter?
Roughly how old is the system?
Where is the property?
Leave your details and we’ll be in touch to book your initial visit.
We’ll ring you to talk it through and arrange a convenient time. Your answers above go with your enquiry, so you won’t have to repeat them.
We’ll talk through what’s happening and book your initial visit. If it’s urgent, call 0800 156 0191.
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You can also reach us through our contact page.