Your solar inverter is showing a red light or fault code?
Don't panic — most inverter warnings are one of a handful of known causes, and some clear themselves. Here's what the lights and codes generally mean, the one safe reset you can try yourself, and exactly when to stop and call a licensed electrician. Straight, safe, no scare tactics.
Reviewed by Josh, Mission Green Energy Team · Updated July 2026
A red light or fault code —
what does it actually mean?
On most inverters a red or flashing red light means the unit has detected a fault and stopped generating — but it doesn't tell you which fault. The exact meaning is specific to your brand and lives in your inverter manual or the manufacturer's app.
Here's the honest starting point: a warning light or a code on the screen is the inverter doing its job — noticing that something is outside safe operating limits and shutting down to protect itself and your system. That's reassuring, not alarming. What it isn't is a universal message. A "red light" or a code like a number-and-letter string means different things on a Fronius, a Sungrow, a GoodWe or a SolarEdge, so the single most useful thing you can do is read the exact code shown and write it down, then check it against your specific inverter's manual or app.
Most red-light situations fall into one of a few general categories:
- Grid voltage or frequency out of range — the grid drifted outside the limits the inverter is allowed to feed into. This is very common and often clears itself once the grid settles.
- Isolation / insulation fault — the inverter has detected a problem in the DC side (wiring, connectors or panels). Take this one seriously.
- DC arc or ground-fault warning — a potential electrical fault on the solar (DC) side. Also one for a professional.
- Overtemperature — the unit is running too hot and has derated or shut down to cool.
- Communications dropout — the inverter has lost its Wi-Fi or monitoring link. Often a nuisance, not a generation fault.
Below we walk through each of these, the one reset you can safely try, and the clear line where you should stop and call a licensed electrician. If your system has stopped feeding the grid entirely, our guide on solar that's stopped exporting to the grid is a good companion read.
What do the status light
colours generally mean?
Colours vary by brand, but the broad pattern is consistent: green is good, orange/amber is a warning, red is a fault. Always confirm your exact model against its manual — there's no universal colour code.
Steady green
The inverter is running normally and generating. On many units green means "grid-connected and feeding in". If you're seeing green in daylight and your solar generation looks normal in the app, there's nothing to do.
Orange / amber
Usually a warning or a grid-related state — for example the grid voltage or frequency drifting out of range, or the inverter waiting to reconnect. Many amber states clear on their own once conditions settle, but note the code if it's shown.
Red (steady or flashing)
The inverter has detected a fault and generally stops generating. This is the one to read carefully: note the exact code, check the manual or app, and if it relates to isolation, arc or ground faults, arrange a professional.
Can I reset the inverter
myself — and how?
Yes — one controlled restart, using the inverter's own isolator switches, in the order your manufacturer specifies, and only if it's safe and simple to reach them. This clears many transient warnings. It is the only DIY step.
The safe restart uses the labelled isolator switches on or beside the inverter — you never open anything. The usual manufacturer sequence is:
- Turn the AC (grid) isolator OFF.
- Turn the DC (solar) isolator OFF.
- Wait a short period — often around five minutes — so the unit fully powers down.
- Turn the DC (solar) isolator back ON.
- Turn the AC (grid) isolator back ON.
Follow the exact order in your manual, because a few brands specify it differently. A controlled restart like this clears many one-off warnings — a brief grid voltage or frequency excursion being the classic example. If the fault clears and stays clear over the next day, you're done.
What you must never do: open the inverter casing, touch or disconnect any DC wiring or connectors, or climb onto the roof. Those are electrician-only tasks, and the DC side of a solar system carries voltage even when the grid is off. If the reset above doesn't reach the fault, or the switches aren't safe and simple to get to, don't push it — call your installer or a licensed electrician.
The safety rule that
never bends.
One controlled reset via the isolators is fine if it's safe and simple. Everything beyond that is a job for a licensed professional. This isn't us being cautious — it's how solar electrical faults are meant to be handled.
Electrical work must be done by a licensed electrician. You can safely turn the labelled AC and DC isolators off (and try the single restart above) only if it is safe and simple to do so — the switches are easy to reach, dry, undamaged, and there's no burning smell, heat, smoke or visible damage. If any of those warning signs are present, isolate if you safely can and get help immediately.
Beyond that one reset, call your installer, a licensed electrician, or a CEC-accredited service for anything more. Specifically, you should never:
- Open the inverter or remove any covers or panels.
- Touch, probe or disconnect DC wiring, connectors, or anything on the solar side — it can carry dangerous voltage even with the grid off.
- Work at height or go onto the roof to inspect panels or cabling.
If a fault keeps returning, or the code points to isolation, arcing or ground faults, that's the clear signal to stop resetting and bring in a professional. We only ever work with SAA-accredited installers and licensed electricians for exactly this reason.
What's actually behind
the most common faults?
Most inverter red lights trace back to one of these categories. Some clear themselves; others are a genuine reason to call a professional. Here's how to tell them apart — without guessing your specific code.
Grid voltage / frequency out of range
The grid drifted outside the limits your inverter is allowed to feed into, so it tripped off to stay compliant. This is one of the most common causes and frequently clears once the grid settles — often within minutes. If it's persistent at the same time each day, it's worth raising with your network.
Isolation / insulation fault
The inverter has detected a problem on the DC side — moisture ingress, a damaged cable, or a degraded connector. Don't keep resetting past this one; isolate if safe and simple and arrange a licensed electrician to investigate.
DC arc or ground-fault warning
A potential electrical fault on the solar (DC) side. These warnings exist to prevent damage, so treat them seriously: leave the equipment closed and get a CEC-accredited installer or licensed electrician to diagnose it.
Overtemperature
The inverter runs too hot and derates or shuts down to protect itself — more likely in direct sun, poor ventilation, or high ambient heat. It usually recovers as it cools; any physical change to shade or airflow should be done by a professional.
Communications / Wi-Fi dropout
The inverter has lost its monitoring link, so the app shows "offline" — but generation itself may be fine. Annoying rather than dangerous. Re-pairing the Wi-Fi per the manual often fixes it; it won't affect the power you're producing.
Something else entirely
Brands have dozens of specific codes we won't guess at here. The exact meaning is in your manual or the manufacturer's support page — so record the code precisely and look it up rather than relying on a general category.
Why does it fault on
hot or sunny days?
Faults that cluster on hot afternoons are usually heat or grid-voltage related — and many are self-limiting rather than a defect. Here's the honest explanation, and why the timing itself is useful information.
Two things tend to be going on when an inverter plays up in the heat. First, overtemperature: inverters generate their own heat and will derate (throttle back) or shut down if they get too hot. That's far more likely when the unit sits in direct sun, is poorly ventilated, or the day is simply very hot. Improving airflow and shade around the inverter can help — but any physical change should be arranged through a professional, not done by opening or moving equipment yourself.
Second, grid voltage rise: on sunny afternoons when a whole street is exporting solar, the local grid voltage can climb and push past the limit your inverter is allowed to feed into. The inverter trips off to stay compliant and usually reconnects automatically once the voltage settles. That's the system working as intended — but if it happens often, it may be a network voltage issue worth flagging.
Either way, the practical move is the same: note the exact code and the time it happens, and pass that to your installer or a licensed electrician. Repeated same-time faults point them straight at ventilation or a grid-voltage problem. If your bills look off alongside the faults, our guide on why a power bill can go up after solar may also help you make sense of what you're seeing in the app and on your statement.
The one thing to do
before you phone anyone.
Record the exact fault code. It's the single most useful piece of information you can give a technician — it often lets them diagnose the problem before they've even arrived, and can save a call-out.
When you contact your installer, a licensed electrician or a CEC-accredited service, the first thing they'll ask is: what does the screen or app actually say? So capture it precisely before you call:
- The exact code — the full number-and-letter string, or the precise wording, not a paraphrase. A photo of the inverter screen or the app is ideal.
- When it happens — time of day, whether it's sunny or hot, whether it clears and comes back.
- What you've already tried — for example the single controlled restart, and whether the fault cleared or returned.
- The brand and model — usually on a label on the side of the inverter and in your handover paperwork.
That handful of details turns a vague "my inverter has a red light" into something a technician can act on quickly. If your system is still under warranty, having the code and history recorded also helps get it resolved without extra diagnostic visits.
So — what should you actually do?
Here's the advice we'd give a friend: read the code, try the one safe reset, and know exactly when to stop and call a professional. That's the whole safe playbook.
If the light is amber or the code points to a grid voltage or frequency issue, there's a good chance it clears itself — and a single controlled restart via the isolators, done safely and simply, will often see it off. If the fault relates to isolation, arcing or ground faults, if it keeps returning after a reset, if there's any burning smell, heat or visible damage, or if the inverter won't come back on at all, stop there and call a licensed electrician or CEC-accredited installer. Never open the inverter, touch DC wiring, or work at height — those are always professional jobs. And whatever you do, record the exact code first: it's the fastest path to a fix.
Inverter red light or fault code?
Your questions, answered.
On most solar inverters a red or flashing red light signals a fault the inverter has detected and stopped generating over, rather than a normal status. What it does not tell you is which fault — the exact meaning is specific to your brand and model and lives in your inverter manual or the manufacturer's app, which will translate the light or on-screen code into plain words. Common general causes behind a red fault light include the grid voltage or frequency being out of range (which often clears itself), an isolation or insulation fault, a DC arc or ground-fault warning, the unit running too hot, or a communications dropout. The safe first move is to read the exact code shown, write it down, and check it against your manual. If the code points to an isolation, arc or ground fault, or if it keeps coming back, treat it as something to isolate (only if that is safe and simple) and have a licensed electrician or CEC-accredited installer look at — never open the inverter yourself.
The colours vary by brand, but the general pattern across most Australian solar inverters is consistent: a steady green light means the inverter is running normally and generating, an orange or amber light usually means a warning or a grid-related issue (for example the grid voltage or frequency drifting out of range, which often clears on its own), and a red light means the inverter has detected a fault and stopped. Flashing versus steady, and combinations of lights, carry their own meanings that differ between makers. Because there is no universal colour code, the honest answer is to confirm your specific model against your inverter manual or the manufacturer's app rather than assuming another brand's meaning. If the light is red or the fault will not clear, note the exact code and, if it relates to isolation, arcing or ground faults, arrange a licensed electrician or CEC-accredited installer.
You can safely try one controlled restart using the inverter's own isolator switches — but only if it is safe and simple, and only in the order your manufacturer specifies. The usual sequence is to turn the AC (grid) isolator off, then the DC (solar) isolator off, wait a short period (often around five minutes so the unit fully powers down), then turn the DC isolator back on, and finally the AC isolator back on. This clears many transient warnings, such as a brief grid voltage or frequency excursion. What you must not do is open the inverter, touch or disconnect any DC wiring, or climb onto the roof — those are electrician-only tasks. If the fault clears and stays clear, you are done. If it comes straight back, or the code points to an isolation, arc or ground fault, stop and call a licensed electrician or your CEC-accredited installer rather than resetting repeatedly.
An isolation, insulation, arc or ground-fault warning is one to take seriously, because it can indicate a real problem with the DC wiring, connectors or panels — moisture ingress, a damaged cable, or a degraded connection — rather than a harmless transient. It is not something to keep resetting past. If your inverter shows this kind of fault, the safe response is to isolate the system only if that is safe and simple to do (turning off the labelled AC and DC isolators per your manual), leave the equipment closed, and arrange a licensed electrician or CEC-accredited installer to investigate. Do not open the inverter, do not touch or probe the DC wiring, and do not go onto the roof. Record the exact fault code so the technician can diagnose it faster. Persistent isolation, arc or ground faults are exactly the situation where professional help is the right call, not a DIY fix.
Faults that appear on hot or very sunny days are often heat or grid-related, and many are self-limiting rather than a defect. Inverters generate their own heat and derate or shut down if they get too hot, so an overtemperature warning is more likely when the unit is in direct sun, poorly ventilated, or the ambient temperature is high — improving airflow and shade around the inverter can help, but any physical change should be done by a professional. Separately, on sunny afternoons when lots of solar is being exported across a neighbourhood, the local grid voltage can rise and push past the inverter's allowed limit, causing it to trip off and often reconnect automatically once the voltage settles. If your inverter faults repeatedly at the same time of day, note the exact code and the time it happens and pass that to your installer or a licensed electrician, as it may point to a ventilation issue or a grid-voltage problem worth raising with your network.
Call a licensed electrician or CEC-accredited installer whenever a fault is more than a one-off that clears with a single controlled restart. Specifically, get professional help if the red light or fault code returns after you reset it, if the code relates to isolation, insulation, arc or ground faults, if there is any sign of burning smell, heat, discolouration or damage, or if the inverter will not turn back on at all. You should also call rather than DIY for anything that would require opening the inverter, touching DC wiring, or working at height — none of which you should ever do yourself. Electrical work must be carried out by a licensed electrician. Before you call, record the exact fault code and note when it happens; that single piece of information often lets the technician diagnose the problem faster and, where it is under warranty, helps get it resolved without extra visits.