Inverter screen blank. Red light on. An error code you've never seen before. Or the app says zero and you're not sure if it's the system or the app. This is the most common service call we get on the Sunshine Coast, and the good news is that a fair share of them turn out to be something simple.
The bad news is that the simple fixes and the dangerous ones look identical from the ground. So this guide is as much about what not to do as what to do.
Short answer: if your solar inverter isn't working, first check it on a sunny day around midday, look for a tripped solar breaker in the switchboard, and note any error code. You can safely try the manufacturer's shutdown and restart sequence printed on the label near your inverter. If the fault comes back, or you see water, scorching or smell burning, switch off at the AC isolator and the solar main switch and call a licensed solar electrician. Anything beyond that sequence and a visual check is licensed electrical work.
How to tell if your solar inverter is working
The inverter is the box, usually on a wall in the garage or outside near the meter box, that converts DC power from your panels into AC power for the house. When it stops, the house keeps running off the grid, so you won't notice anything except the bill.
Do these checks in daylight, ideally on a clear day between about 10am and 2pm:
- Look at the display or status lights. Most inverters show current output in watts or kilowatts and a running daily total. A green light usually means it's producing; red or orange usually means a fault. Your manual explains the exact colours for your model.
- Check the output is reasonable. Reading zero, or a tiny number, in full sun is a red flag. Reading low on a heavily overcast day is normal.
- Check the switchboard. Look for a breaker labelled "solar", "inverter" or "PV" that's in the off or tripped position.
- Check your monitoring app. Look at the last few weeks, not just today. A flat line that starts on a particular day tells you when it stopped.
- Check your bill. If export credits have dropped sharply compared with the same season last year, generation probably has too.
Two things that look like faults but usually aren't:
- Blank screen at night. Inverters go to sleep when the panels stop producing. That's normal.
- A grid error during a blackout. Grid-connected inverters are required to shut down when the grid goes down, so they don't send power into lines that crews may be working on. Once the grid is back, the inverter reconnects on its own after running its checks.
Safety first: what you can and can't do yourself
Read this section before touching anything.
A solar array is a live DC generator whenever the sun is on it. Switching the inverter off, or flicking the solar breaker in the switchboard, stops it feeding the house. It does not make the panels, the roof cabling or the DC side of the inverter safe. Those stay energised as long as there's daylight.
What a homeowner can do:
- Read the inverter screen, lights and app
- Check for and note any error code
- Check whether a solar breaker has tripped in the switchboard
- Follow the shutdown and start-up sequence on the label at your inverter or switchboard
- Look, from the ground, for obvious damage: a cracked panel, a hanging cable, a broken isolator enclosure
What a homeowner should not do:
- Open the inverter, an isolator enclosure or a junction box
- Unplug, re-plug or touch DC connectors or cabling
- Go on the roof, or touch a rooftop isolator
- Reset a breaker that keeps tripping, over and over
- Hose the panels or isolators to "clear" a fault
In Queensland, work on the DC side of a solar system is licensed electrical work. Isolating, disconnecting, opening enclosures and handling connectors are not handyman jobs, whatever a cheap quote says.
Stop and call an electrician immediately if you see or smell any of these:
- A burning smell near the inverter or an isolator
- Scorch marks, melted plastic or discolouration
- Water sitting inside an isolator enclosure
- Crackling, buzzing or arcing sounds
- A breaker that trips again straight after being reset
In those cases, switch the system off at the AC isolator and the solar main switch in the switchboard if you can do so safely, keep clear, and call.
How do I reboot my solar system?
A restart clears some temporary faults, particularly after a grid disturbance or a communications glitch. It's the one hands-on step the manufacturer intends owners to be able to do.
Always follow the shutdown procedure printed on the label at your inverter or switchboard. Most installations have one. It's specific to your equipment, and it overrides any general guide, including this one.
As a general pattern, shutdown runs from the AC side to the DC side:
- Turn off the AC side first. That's the solar supply main switch in your switchboard, and the AC isolator next to the inverter if you have one.
- Then turn off the DC isolator at the inverter, if your label tells you to.
- Wait a few minutes for the screen to go dark and the unit to fully power down.
Start-up is the reverse:
- Turn the DC isolator back on at the inverter.
- Then turn the AC side back on: the AC isolator at the inverter, then the solar supply main switch in the switchboard.
- Give it a few minutes. The inverter checks the grid before it starts exporting, so it won't jump straight back to full output.
Some systems with a battery or a hybrid inverter have extra steps, or a different order. Again, the label wins.
If it doesn't come back, or the same error reappears, stop. Repeatedly cycling a faulted inverter won't fix it, and in some fault conditions it makes things worse. Write down the error code, take a photo of the screen, and call.
Common solar inverter errors and what they usually mean
Every brand uses different codes, so check your manual for the exact wording. These are the patterns we see most often:
| What you see | What it usually means | Owner-safe action |
|---|---|---|
| Zero output in full sun | A failed DC isolator, a tripped breaker or switchboard fault, or a dead inverter | Check the breaker, try the labelled restart once, then call |
| Insulation or "ISO" fault | Moisture has got into a DC connector or junction box, or cabling insulation has broken down | Don't restart repeatedly. Call. This one can be a safety issue |
| Grid overvoltage | Network voltage is above the limit the inverter is allowed to export into | Note the times it happens. An electrician can record readings and raise it with Energex |
| Grid lost / no grid | Power outage, or a problem on the AC side | If there's a blackout, wait for the grid. Otherwise check the breaker and call |
| Monitoring offline | Usually a new router or changed Wi-Fi password, sometimes a failed Wi-Fi dongle | Often fixable by reconnecting Wi-Fi; check the inverter screen to confirm it's still producing |
| Fan or over-temperature warning | Blocked or failed cooling fan, or the inverter is in direct afternoon sun | Clear anything stacked around it; don't open it. Call if it persists |
Overvoltage deserves a special mention on the Sunshine Coast. On streets with a lot of solar, network voltage can sit high in the middle of the day, and inverters are required to back off or disconnect when it does. The inverter isn't faulty, but you're losing generation. The fix involves measuring the voltage, checking the inverter settings against AS/NZS 4777.2 and current network requirements, and raising it with the network where the readings justify it.
What could be the reasons why my solar panels are not producing power?
If the inverter looks healthy but output is low or zero, the problem may be upstream of it:
- A failed rooftop DC isolator. Rooftop isolators are a known and widespread failure point on older Australian installs. Enclosures crack under UV, water gets in, and the contacts arc. Treat any sign of this as urgent.
- Water in a connector or junction box, usually showing up as an insulation fault.
- Damaged cabling, from UV, rodents or other trades on the roof.
- Shading that has grown over the years, or a new building next door.
- Dirty panels, particularly bird droppings and lichen, which bake on and cause hot spots.
- Cracked or degraded panels, from hail, storm debris or someone walking on them during other roof work.
- The system was switched off by an electrician or roofer and never switched back on. It happens more than you'd think.
None of these are DIY fixes beyond a look from the ground. All of them involve the live DC side.
How long do inverters usually last?
Inverters are generally the first major component in a solar system to fail, well before the panels. Panels commonly carry 25-year manufacturer warranties; the inverter running them usually won't last that long, and you should expect to replace it at least once over the life of the panels.
We don't put a single number on inverter life because it varies with the brand, the model, how hot the install location gets, and how hard the inverter has been worked. What we can say is that a large share of Sunshine Coast systems installed during the 2011 to 2013 rebate wave are already on their second inverter or due one.
Things that shorten inverter life:
- Mounting in direct afternoon sun, or in a hot, unventilated space
- Dust and insects blocking cooling fans
- An array that's too big for the inverter
- Coastal salt air corroding terminals and enclosures
Your inverter's warranty card will tell you its manufacturer warranty term. It's often shorter than the panel warranty, so check it before assuming you're covered.
Repair or replace?
Some inverter faults are genuinely repairable in the field: blocked or failed cooling fans, surge protection devices, loose terminations, corroded DC inputs and firmware problems. A failed main power board generally is not, and a reputable electrician will tell you so rather than sell you a repair that won't hold.
Replacement makes more sense when:
- The main board has failed
- The manufacturer has left the Australian market, so there are no parts or warranty support
- You're planning to add panels or a battery, in which case a hybrid or battery-ready inverter is often better value than the same model again
We cover the options in detail in our guide to solar inverter replacement. If you'd like it looked at, our solar inverter repair service starts with a free phone diagnosis: tell us what the screen or app is showing and we'll tell you whether it's something you can safely reset yourself or something that needs an electrician on site. We service systems we didn't install.
What about the warranty?
If the inverter is still within its manufacturer warranty, the claim usually runs through your installer, who diagnoses it and lodges it with the manufacturer or their Australian distributor.
If your installer has closed down, don't assume the warranty went with them. Panel and inverter warranties are manufacturer warranties and often survive the installer going under. What you lose is the installer's workmanship warranty. We take on these orphaned systems regularly: identify what's on the roof, record model and serial numbers, check what cover remains, and lodge the claim. You can start that on our warranty and service request page.
Have these ready when you call anyone about an inverter fault:
- A photo of the inverter screen showing the error
- A photo of the inverter's model and serial number label
- A photo of your switchboard
- Roughly when the problem started, if your app shows it
Frequently asked questions
How do I tell if my solar inverter is working?
Check it in daylight around midday. A working inverter normally shows current output in watts or kilowatts and a green or normal status light. Zero output in full sun, a red or orange light, an error code on screen, or a flat line in your monitoring app all suggest a fault. A blank screen at night is normal.
How do I reboot my solar system?
Follow the shutdown procedure on the label at your inverter or switchboard. In general you turn off the AC side first (the solar supply main switch and AC isolator), then the DC isolator at the inverter, wait a few minutes, then reverse the order to start up. If the error returns, don't keep restarting it; call a licensed solar electrician.
How long do inverters usually last?
Inverters are usually the first major part of a solar system to fail, well before the panels, which commonly carry 25-year warranties. Expect to replace an inverter at least once over the life of your panels. Many systems installed between 2011 and 2013 are already on their second inverter.
What could be the reasons why my solar panels are not producing power?
The usual culprits are a failed rooftop DC isolator, a tripped breaker, a dead inverter, water in a DC connector causing an insulation fault, high grid voltage forcing the inverter to back off, or new shading. Dirty or cracked panels reduce output rather than stopping it. Anything on the DC side needs a licensed electrician.
Is it safe to turn off my solar inverter?
Yes, following the shutdown procedure on your system's label is safe and is what it's designed for. But turning the inverter off doesn't make the panels or roof cabling safe. They stay live whenever there's daylight, so never open enclosures or touch DC cabling.
