You can tell if your solar panels are working by checking the inverter indicator lights, reviewing your monitoring app for daily generation data, and comparing your electricity bill to previous periods. A drop in any of these signals a potential fault.
Many Central Coast, Newcastle, and Hunter Valley homes have solar systems that underperform without the owner realising it. Restore Electrical provides licensed solar inspections, fault diagnosis, and repair services across the region. This guide covers how to check your solar panel performance yourself, what common faults look like, and when you need a qualified electrician.
Most Solar Faults Go Unnoticed for Months
Solar panels work silently in the background. There’s no engine noise, no moving parts, and no obvious sign when something goes wrong. That’s exactly why most faults go undetected. In my experience across the Central Coast and Hunter Valley, homeowners typically discover a problem only when their electricity bill jumps or a monitoring alert finally triggers.
According to the Clean Energy Regulator, inspections of small-scale renewable energy systems in Australia have consistently found substandard or unsafe installations across a significant percentage of systems checked. NSW alone has over 1.1 million small-scale solar systems installed as of late 2025.
With that many systems across the state, even a small percentage of faults translates to tens of thousands of underperforming rooftops. The sooner you spot a problem, the sooner you stop losing money.
Quick Signs Your Solar Panels Might Not Be Working Properly
Before diving into detailed diagnostics, these are the first warning signs that tell you something isn’t right with your solar system:
Your electricity bill has increased
If your power costs have risen over the past quarter despite no change in household usage, your solar system may not be generating as expected. Compare your current bill to the same period last year. Seasonal variation is normal, but a significant jump warrants investigation.
The inverter shows a red or orange light
A green light on your inverter during daylight hours means the system is generating. A red or orange light indicates a fault, an error code, or a system shutdown. Check the display screen for a specific error message.
Your monitoring app shows zero or low output
Most modern inverters connect to a smartphone app that tracks daily generation in real time. If the app hasn’t updated in days, or shows output well below your usual levels on a sunny day, something is off.
The inverter screen is completely blank
A blank screen during daylight hours could mean the inverter has lost power or failed entirely. Check whether the DC isolator switch is in the ON position before calling for help.
You can see physical damage from the ground
Cracked glass, heavy bird droppings, accumulated leaf debris, or visible water staining on the panels all reduce output. Never climb onto the roof to check. Use binoculars or a camera zoom from ground level.
More: Voltage Fluctuations and Flickering Lights Explained
How to Check If Your Solar Panels Are Working: Step by Step
You can safely run through these checks without any tools or electrical knowledge. If anything looks wrong at any step, that’s your signal to call a licensed electrician:
Check the Inverter Lights and Display
Walk to your inverter (usually mounted on an external wall near the meter board or switchboard). On a sunny day, a green indicator light confirms the system is converting solar energy into usable electricity. A red or amber light, a fault code, or a blank screen all suggest a problem. Note down any error codes shown on the display.
Open Your Monitoring App
Log into the monitoring app connected to your inverter. Most brands provide one, including Fronius, SolarEdge, Enphase, Sungrow, and GoodWe. Check today’s output and compare it against similar sunny days from the past few weeks. A healthy system on the Central Coast should generate between 3.5 and 5.5 kWh per kilowatt of installed capacity on a clear summer day.
Review Your Electricity Bill
Your bill shows how much power you imported from the grid and, if you have a smart meter, how much you exported. If your import has increased while export has dropped, your system is generating less. This comparison works best against the same billing period from the previous year.
Check the Isolator Switches
Your solar system has at least two isolator switches: a DC isolator near the inverter and an AC isolator at the switchboard. Both must be in the ON position for the system to operate. If either has been accidentally switched off, your system will produce nothing. Do not open the DC isolator enclosure. Just confirm the switch position.
Look at the Panels from Ground Level
From the ground, scan for visible dirt, bird nesting, fallen branches, or cracked glass. Panels covered in grime lose efficiency gradually. Panels with physical damage can develop hot spots or stop producing entirely. If you notice anything concerning, a professional inspection is the safest next step.
Common Causes of Reduced Solar Performance on the Central Coast
Different faults produce different symptoms. This table helps you match what you’re seeing to the most likely cause and how urgently it needs attention:
| What You’re Seeing | Most Likely Cause | Urgency |
| Inverter shows red/orange light | Inverter fault, grid voltage issue, or DC wiring problem | High: call an electrician |
| Inverter screen is completely blank | Loss of DC supply, blown fuse, or inverter failure | High: call an electrician |
| Gradual drop in daily output | Dirty panels, shading from new tree growth, or panel degradation | Medium: schedule inspection |
| Sudden drop to zero output | Tripped AC isolator, DC isolator off, or inverter shutdown | Medium: check isolators first |
| Bill increased despite sunny weather | System generating but not exporting, tariff change, or meter fault | Medium: compare monitoring data |
| Monitoring app not updating | Wi-Fi disconnection or inverter communication fault | Low: restart the router first |
| Visible cracks or water marks on panels | Physical damage from hail, debris, or manufacturing defect | Medium: book inspection |
| Burning smell near inverter or DC isolator | Overheating component, arcing, or water ingress into isolator | Urgent: switch off and call immediately |
Why the Central Coast and Hunter Valley Present Unique Solar Challenges
Location-specific factors directly affect how long your solar system performs at its best. The Central Coast, Newcastle, and Hunter Valley have conditions that create particular risks:
- Salt air corrosion on DC isolators. Coastal suburbs like Terrigal, Avoca Beach, The Entrance, and Umina Beach sit in a salt spray zone. DC isolator enclosures, cable connectors, and inverter terminals corrode faster in these conditions. According to the Australian Government’s Your Home guide, galvanically different metals in contact with each other will corrode and must be separated by an isolating material. Salt air accelerates this process significantly.
- Bird and possum nesting under panels. Homes backing onto bushland in Kariong, Niagara Park, Lisarow, and Ourimbah see frequent issues with possums and birds nesting beneath panels. Nesting debris blocks airflow, traps moisture, and can damage wiring insulation. I’ve pulled possum nests from under panels across the Central Coast that had been silently degrading system output for years.
- Storm debris and hail damage. The Central Coast regularly experiences severe thunderstorms and east coast lows. Hail can crack panel glass without shattering it, creating micro-fractures that reduce output over time. Fallen branches can also shift panel mounting, breaking cable connections underneath.
- Older systems approaching inverter end of life. Many Central Coast homes installed solar systems between 2010 and 2015 during the NSW Solar Bonus Scheme era. Those systems are now 10 to 15 years old, and most residential inverters have a lifespan of 8 to 12 years. If your system was installed during that period, your inverter may be due for replacement. A solar system upgrade can restore full performance and take advantage of newer, more efficient technology.
- Shading from mature vegetation. Suburbs with established tree canopies like Erina Heights, Bateau Bay, and Woy Woy can experience increasing shading as trees grow. Even partial shading on one panel can reduce output across an entire string in older systems without panel-level optimisers.
The DC Isolator: The Most Common Safety Risk in Solar Systems
The DC isolator is the single component most likely to cause a serious safety issue in a residential solar system. It’s a manual switch that disconnects the high-voltage DC current flowing from the panels to the inverter. When it fails, the consequences can be severe.
According to the Clean Energy Regulator, a professional solar check should include confirming that switches do not have any defects and that wiring has not deteriorated or been damaged. DC isolators are specifically identified as the most common source of safety incidents in solar PV systems, including overheating and fires.
Here’s what you need to know:
What Goes Wrong
Water ingress is the primary cause of DC isolator failure. When moisture enters the enclosure, it corrodes internal contacts and creates arcing, which generates extreme heat. Over time, this can melt the switch housing or ignite surrounding materials. Systems installed before 2018 are at higher risk because earlier isolator designs had weaker weather sealing.
What to Watch For
If you notice a burning smell near the inverter or see scorch marks, discolouration, or melting on the DC isolator enclosure, do not touch it. Switch off the AC isolator at the switchboard instead and call an electrician immediately.
When to Get It Checked
The NSW Government’s guide to solar panels states that after your solar panels are installed, a licensed electrician must check that the system is safe and provide a Certificate of Compliance for Electrical Work. AS/NZS 5033, the Australian Standard for photovoltaic array installation, recommends annual inspection of DC isolators and all system components.
What a Licensed Electrician Actually Tests During a Solar Inspection
When you call a qualified electrician for a solar system check, the inspection goes well beyond what any homeowner can safely do. Here’s what the process involves:
Insulation resistance testing on DC strings
Using a megohmmeter, the electrician tests the insulation resistance of the DC wiring between the panels and the inverter. Low readings indicate insulation breakdown, which can cause earth faults, reduced output, or fire risk.
String voltage and current measurement
Each string of panels should produce a predictable voltage and current based on the number and rating of the panels. Significant variance between strings indicates a faulty panel, a poor connection, or shading impact.
Inverter diagnostics and error log review
The electrician accesses the inverter’s internal error log to identify recurring faults, grid voltage events, or performance limitations that the homeowner’s app may not display.
DC and AC isolator condition assessment
Visual and functional testing of all isolator switches, checking for corrosion, heat damage, water ingress, and correct operation.
Earth fault loop impedance testing
Verifies the safety of the earthing system connected to the solar installation, ensuring that any fault will trip the protective devices quickly.
Panel visual inspection from roof level
A qualified professional with appropriate safety equipment inspects the panels directly for micro-cracks, hot spots (using thermal imaging where available), damaged connectors, and mounting integrity.
After completing a solar inspection and fault detection visit for a homeowner on the Central Coast, the team received this feedback: “Great service, responsive, easy to work with, no cost surprises and good commercial advice on future house works.”Gerard Filgate. That kind of straightforward advice is what every solar system owner deserves after an inspection.
How to Keep Your Solar System Performing at Its Best
Prevention is cheaper than repair. These steps help maintain your solar system’s output and extend its lifespan:
Hose Panels from the Ground When Dirty
If your panels look visibly dirty after a long dry spell, a gentle hose from ground level is usually enough to clear dust and light debris. Don’t use a pressure washer. Don’t use detergents. And don’t climb the roof. If the dirt won’t budge, hire a professional cleaner with the right safety equipment.
Test Your Inverter Monitoring Monthly
Set a calendar reminder to check your monitoring app on the first of each month. Compare that day’s output to the same day in previous months. You’ll quickly spot any decline.
Book a Professional Inspection Every Two to Five Years
The SafeWork NSW guide to safe solar panel installation outlines the safety duties that apply to anyone working on or maintaining solar PV systems. AS/NZS 5033 recommends annual inspections. As a practical minimum, have your system checked by a licensed electrician every two years, or sooner if you notice any warning signs. This is especially important for residential properties with systems older than five years.
Address Pest Problems Early
If you see birds nesting under your panels or evidence of possum activity in the roof space, have it addressed before wiring damage occurs. Critter guards can be fitted around the panel array to prevent access.
Consider a Battery to Maximise Your Solar Investment
If your system generates more power than you use during the day, a solar battery stores that excess energy for evening use. This reduces grid imports and makes your solar investment work harder, especially as feed-in tariff rates continue to drop.
More: Why a Level 2 Electrician Is Essential for Mains and Metering Work
When Your Solar System Needs Urgent Attention
Most solar issues are gradual. But some situations require immediate action:
- Burning smell or visible scorch marks. Turn off the AC isolator at the switchboard immediately. Do not touch the DC isolator. Call a licensed electrician for urgent assessment.
- Crackling or buzzing sounds from the inverter or roof. This can indicate arcing in the DC wiring or a failing connection. Switch off the system at the AC isolator and get professional help.
- Water pooling around the inverter or isolator. After heavy rain, check for water accumulation near the inverter or DC isolator enclosure. If water has entered the enclosure, do not touch it. Contact your local solar electrician immediately.
- Inverter displaying “isolation fault” or “earth fault” error. These error codes indicate a potential safety hazard in the DC wiring. The system should not be restarted until a qualified electrician has tested and cleared the fault.
Restore Electrical provides same-day solar fault diagnosis and repair services across the Central Coast and Newcastle for exactly these situations.
What to Look for in a Solar Electrician
Not every electrician is qualified to work on solar PV systems. When choosing someone to inspect or repair your solar installation, check for the following:
- Licensed electrician with solar experience. All electrical work on solar systems in NSW must be performed by a licensed electrician. For installation work, the electrician should hold accreditation through Solar Accreditation Australia (formerly CEC accreditation).
- Proper diagnostic equipment. A standard multimeter isn’t enough for solar fault finding. The electrician should carry a megohmmeter for insulation testing, a DC clamp meter, and ideally a thermal imaging camera for panel inspection.
- Familiarity with your inverter brand. Different inverter manufacturers have different fault codes, diagnostics processes, and warranty procedures. An electrician familiar with your brand can diagnose faster and advise on warranty claims.
- Level 2 ASP accreditation for grid-side work. If the solar fault involves the meter, grid connection, or consumer mains, a Level 2 Accredited Service Provider is required. Standard electricians can’t legally work on the supply side. Learn more about our team’s qualifications on our solar services page.
Areas We Service
Restore Electrical provides solar panel inspections, fault diagnosis, inverter replacements, and system upgrades across the Central Coast, Newcastle, and Hunter Valley, including Gosford, Terrigal, Erina, Umina Beach, Woy Woy, Bateau Bay, The Entrance, Avoca Beach, Kariong, Niagara Park, Lisarow, Ourimbah, Charlestown, Newcastle, Wallsend, Maitland, Lake Macquarie, Hunter Valley, and surrounding areas.
Get Your Solar System Checked by a Licensed Central Coast Electrician
If your solar panels aren’t performing like they should, don’t wait for the next bill shock. Call Restore Electrical on 02 4006 8326 for a thorough solar inspection and honest advice. Licensed electricians, same-day service, fixed upfront pricing, and a lifetime labour warranty on all work. $50 off your first service.
Frequently Asked Questions
How do I know if my solar panels are working properly?
Check the inverter for a green indicator light during daylight hours, review your monitoring app for daily generation data, and compare your electricity bill against the same period last year for any unexpected increase.
What does a red light on my solar inverter mean?
A red or orange light typically indicates a system fault, a grid voltage issue, or an internal inverter error. Note the error code displayed on the screen and contact a licensed electrician on the Central Coast for diagnosis.
How often should solar panels be inspected?
AS/NZS 5033 recommends annual inspection of solar PV systems and components. As a practical minimum, book a professional check every two years, or sooner if you notice warning signs like reduced output or unusual sounds.
Can dirty solar panels stop working entirely?
Heavy dirt buildup, bird droppings, and leaf debris can significantly reduce output but rarely stop generation completely. A gentle hose from ground level clears most surface dirt. For stubborn grime, hire a professional with roof access equipment.
Why has my electricity bill gone up even though I have solar?
Common causes include a faulty inverter producing less power, a tariff change after a smart meter installation, increased household consumption, or shading from new tree growth, reducing panel output. Check your monitoring app data first.
How long do solar inverters last in Australia?
Most residential inverters last 8 to 12 years. Systems installed during the NSW Solar Bonus Scheme era, around 2010 to 2015, may now be approaching or past their inverter’s expected lifespan and could benefit from a replacement.
