Old Solar Inverter in Unanderra? Repair, Replace or Go Hybrid

If your solar inverter in Unanderra, Cordeaux Heights or Farmborough Heights has stopped working, the panels are almost certainly fine. Inverters usually wear out long before panels do, and plenty of Illawarra systems from the early 2010s are still on their original one. This guide covers how to tell the inverter has failed, when repair makes sense, when to replace it, and when a hybrid inverter is the better buy.

The short answer

• Still under warranty: claim it. Contact the installer or the manufacturer before anyone else touches it.

• Out of warranty and more than about ten years old: replacement is usually the better spend. Repairs on older string inverters are often uneconomic or impossible.

• Battery likely in the next few years: replace it with a hybrid inverter now, so the battery can be added without changing inverters twice.

• The panels stay. A replacement inverter is matched to the panels you already have.

Signs your inverter has failed

Inverters tell you when something is wrong, if you know where to look.

• The display or status light shows a fault, a red light, or nothing at all on a sunny day.

• Your monitoring app shows zero output, or the same output on clear and cloudy days.

• Your bill jumps and the feed-in credit drops to nothing.

• The inverter clicks, hums or restarts repeatedly during the day.

Write down any error code before calling anyone. It often identifies the fault straight away. If the inverter is off, check the solar main switch on the switchboard and the AC and DC isolators beside the inverter are on before assuming the worst. Do not open the inverter: the DC side stays live whenever the sun is on the panels.

Repair or replace?

A newer inverter of a well-supported brand can be worth repairing. An old inverter from a brand that has left Australia rarely is. Our inverter upgrade guide compares the replacement options in more detail.

Choosing a replacement inverter

Match it to your panels

The new inverter has to suit the voltage and current of the panels already on your roof. A system with 5kW of panels is normally matched with a 5kW inverter or close to it. We read the panel labels and the original paperwork, and if the old panels are wired in a way the new inverter cannot accept, the strings are rearranged at the same visit.

Think about a hybrid

A hybrid inverter runs panels and a battery together. If a battery is a real possibility, fitting a hybrid now avoids buying a second inverter later. If a battery is not on the cards, a standard inverter is cheaper. Our guide to solar battery costs in Wollongong will help you decide.

Check the connection rules

A replacement inverter has to meet today's standards, not the ones your system was approved under. In the Illawarra, flexible export connections become the default for eligible new and upgraded systems from November 2026, and they need an internet-connected inverter that meets the CSIP-AUS standard. We lodge any paperwork the network needs and confirm your export limit. Our Illawarra solar guide explains the export rules.

Use it as a reason to look at the panels

If your system is small and the roof has space, an inverter replacement is a sensible moment to ask whether more panels are worth adding. The solar savings calculator shows what extra capacity would be worth. Adding capacity is a bigger job than swapping an inverter and needs its own approval, but it is cheaper done together than separately.

What an inverter replacement involves

1. Check. We confirm the fault, read the panel and inverter labels, and check the switchboard and isolators.

2. Quote. The new inverter, any rewiring, and any paperwork, itemised.

3. Swap. The old inverter comes off the wall and the new one goes on. Most replacements are done in a few hours.

4. Commission. We test the system, set the export limit and connect the monitoring.

On a steep or two-storey home in Cordeaux Heights or Farmborough Heights, there is good news: the inverter is on a wall, so a straight replacement rarely needs anyone on the roof. The exception is an older system with a DC isolator switch mounted beside the panels. Those are a known weak point, and we check it at the same visit. If roof work is needed, the access and fall protection described on our Unanderra solar page apply.

Does a new inverter get a rebate?

No. The federal STC discount applies to new solar panel capacity, not to an inverter replacement on its own. If you add panels at the same time, the new panels can earn certificates, which the solar rebate calculator works out. A battery added with a hybrid inverter can qualify for the federal battery discount, which our battery rebate calculator works out.

Common questions

How long does a solar inverter last?

Commonly ten to fifteen years, depending on the brand, the heat it sits in and how hard it works. Panels usually last much longer, which is why most systems need one inverter replacement in their lifetime.

Can I replace my inverter without replacing the panels?

Yes, in almost every case. The new inverter is chosen to match the panels already on your roof.

Should I move to a hybrid inverter?

If you expect to add a battery within a few years, yes. If not, a standard inverter costs less and does the job.

Where should the new inverter go?

Out of direct afternoon sun where possible, with clearance for ventilation. Heat shortens inverter life, so a shaded wall or a garage is better than a west-facing wall in full sun.

Do you replace inverters on systems you did not install?

Yes. We check the existing panels and wiring first, then quote the replacement. We work across the Illawarra, from Wollongong and Figtree to Dapto.

Next step

Send us a photo of the inverter label and any error code, and we will tell you whether it looks like a repair or a replacement. For a new system or a battery, the solar system size calculator gives you an estimate in two minutes. See how we install in Unanderra.