If your solar inverter is showing an error code, flashing red lights, or sending fault messages in the app, it’s not something you should ignore.

Solar systems don’t usually fail instantly.
They give warning signs first, and error codes are one of the clearest signals that something is wrong.

Some codes are minor and clear themselves.
But others can mean fire risk, isolation faults, damaged wiring, or inverter shutdown, especially during Brisbane’s heat and storm season.

This guide explains what the most common solar error codes mean, and which ones require urgent action.

First: What an Error Code Actually Means

Your inverter constantly checks:

• solar panel voltage

• grid voltage

• insulation resistance

• temperature levels

• safety isolators

• internal electrical components

When something goes outside the safe range, it shows an error code and may shut down to protect itself.

So the inverter isn’t “being annoying”, it’s trying to stop damage.

The Most Common Solar Error Codes (And What They Mean)

Below are the most common fault categories Brisbane homeowners see.

1. Isolation Fault / Earth Fault (DANGEROUS)

This is one of the most serious solar faults.

What it means:

Electricity may be leaking from the system into wiring, roof structures, or moisture.

Common causes:

• damaged DC cable

• water ingress in rooftop connections

• cracked insulation

• faulty solar panels

• rodents chewing cables

Why it’s dangerous:

Isolation faults can cause electric shock risks and potential fire hazards.

 What to do now:
Turn the solar system off and call a licensed solar electrician.

2. Grid Overvoltage (COMMON IN BRISBANE)

This is one of the most common solar shutdown reasons.

What it means:

The inverter is detecting too-high voltage from the grid and shuts down to stay safe.

Common causes:

• too much solar feeding into the grid in your area

• voltage spikes during hot afternoons

• weak or overloaded local network supply

What to do:
If it happens repeatedly, you may need voltage testing and compliance adjustment.

3. Grid Undervoltage / Grid Loss

What it means:

The inverter is not detecting stable grid power.

Common causes:

• street power interruptions

• loose neutral connections

• storm-related outages

• unstable grid during peak demand

What to do:
If it happens once, it may just be the grid.
If it happens regularly, an electrician should check your supply.

4. Overtemperature / Inverter Too Hot (VERY COMMON IN SUMMER)

What it means:

Your inverter is overheating and shutting down to protect itself.

Common causes:

• inverter installed in direct sun

• poor ventilation

• Brisbane heat waves

• blocked fan or airflow

What to do:
Check airflow, shade, and placement.
If it keeps happening, you may need relocation or cooling protection.

5. PV Overvoltage

What it means:

The solar input voltage is too high.

Common causes:

• incorrect panel string design

• wrong inverter sizing

• faulty MPPT tracker

• wiring fault

What to do:
This is a professional inspection issue. Don’t ignore it.

6. DC Overcurrent / DC Fault

What it means:

The inverter detected dangerous current flow on the solar DC side.

Common causes:

• panel fault

• short circuit in DC wiring

• isolator breakdown

• cable damage

What to do:
Turn the system off and book a licensed technician.

7. Relay Fault / Internal Fault

What it means:

Internal inverter components are failing.

Common causes:

• aging inverter

• damaged internal electronics

• lightning strike or surge

• worn out capacitors

What to do:
If your system is older than 7–10 years, this could mean replacement is approaching.

8. Arc Fault / AFDD Error (DANGEROUS)

What it means:

There may be arcing in solar wiring. Sparks occurring inside a connection.

Common causes:

• loose connectors

• damaged wiring

• moisture inside junctions

Why it’s dangerous:

Arcing is one of the biggest causes of solar fires.

What to do immediately:
Turn off the solar and get an urgent inspection.

9. Communication Error / Wi-Fi Drop

What it means:

Your inverter can’t communicate with your monitoring system.

Common causes:

• Wi-Fi down

• router change

• faulty inverter comms module

What to do:
If solar production is still normal, this may only be monitoring-related.
If production drops too, it may indicate inverter instability.

The Solar Error Codes That Should NEVER Be Ignored

If you see any of these, treat it as urgent:

• Isolation fault

• Arc fault

• Burning smell

• Red flashing light

• Inverter overheating repeatedly

• System shutting down daily

• Melted isolator or discolouration

These faults can lead to:

• total solar shutdown

• electrical fire risk

• voided warranties

• damage to household appliances

• power bill increases
  
  

Error Codes Are Your Solar System’s Warning System

Solar systems rarely fail without warning.
Error codes exist so you can fix the issue early before it turns into:

• expensive repairs

• full inverter replacement

• dangerous electrical faults

If your inverter is showing faults repeatedly, it’s worth getting checked early.

👉 Need solar fault testing or inverter diagnostics in Brisbane?
Call Exclusive Electrical & Air for a licensed inspection.