Solar failure: 5 simple checks before calling a technician

Is your solar system down? Keep calm and check first!

Is your monitoring showing abnormally low or zero production? Has your electricity bill suddenly gone up? Before contacting a technician and incurring repair costs, you should know that 80% of solar production problems can be identified and often resolved by the owner himself.

Photovoltaic systems are robust and reliable, but like all electronic equipment, they can sometimes malfunction. The good news? Most of these problems are easy to diagnose, and don't necessarily require specialist intervention.

In this article, we take you step-by-step through the 5 essential checks to carry out when your solar system seems to be malfunctioning. These simple checks will not only save you money on breakdown costs, they'll also help you get your system back up and running as quickly as possible.

Why perform these preliminary checks?

There are several significant advantages to taking a few minutes to inspect your system before calling in an expert:

• Financial savings: A technician's visit usually costs between €80 and €150, even if the problem turns out to be a simple reset or tripped circuit-breaker
• Time savings: An accurate preliminary diagnosis enables the technician to come prepared with the right equipment, reducing intervention time
• Understanding your system: These checks familiarize you with the key components of your installation, making you more self-reliant
• Immediate resolution: In many cases, you'll be able to solve the problem instantly

"The first time my production dropped, I panicked. By following a few simple tips, I realized it was just a circuit breaker. It saved me €150 in travel expenses!"

-

Mr Dubois, owner of a solar installation for 3 years

5 essential checks in the event of a power failure

Follow these steps in order for an effective diagnosis. Always prioritize your own safety, and don't handle electrical equipment if you're not comfortable.

Check #1: Weather and environment

This is the most frequent and simplest cause of a drop in production. Solar panels depend on sunlight, and even a slight obstruction can significantly impact their output.

What to check:

1. Current weather conditions: Low output is normal on overcast, rainy or foggy days. At night, early in the morning or late in the evening, production is naturally reduced or nil
2. Cast shadows: Look for any new obstacles casting shadows on your panels: overgrown trees, new construction, antennas, or accumulations of dead leaves
3. Surface condition of panels: Check for snow, frost, leaves, bird droppings or heavy dust

Possible actions:

• Wait for a sunny day to confirm if the problem persists
• If the obstruction is temporary and safely accessible, clean gently with clear water
• As for snow, it usually melts on its own - never attempt to clear it with tools

Check #2: Inverter status and diagnostics

The inverter is the brain of your system. It converts direct current from the panels into usable alternating current. It is also the component most likely to malfunction.

What to check on your inverter :

1. Display and indicators:
   • Steady green light = normal operation
   • Orange/yellow light = warning or standby
   • Red light = error or malfunction
   • Screen off = power problem

2. Error codes: Note any messages or codes displayed on the screen
3. Sound behavior: A slight humming sound is normal, but clicks or complete silence may indicate a problem

Simple troubleshooting :

1. Consult your UPSmanual to decipher error messages

Attempt

1. a restart (only if you're comfortable):
   • Switch off the AC circuit breaker, then the DC circuit breaker
   • Wait 5 minutes

Switch on again

1. • in reverse order (DC then AC)

2. Check the ventilation: clean the ventilation grilles if they're clogged

If your inverter displays persistent errors, it may need to be replaced. Discover our range of solar inverters for reliable, high-performance replacement solutions.

Check #3: Electrical protection and circuit breakers

A "blown" circuit breaker is a very common and easily solved cause of production stoppage. This check only takes a few minutes, but resolves around 30% of reported problems.

Circuit breakers to be checked :

1. Photovoltaic main circuit breaker: In your electrical panel, look for the one labeled "PV", "Solar" or "Inverter"
2. Inverter AC and DC circuit breakers: Located near the inverter or integrated
3. Earth leakage circuit breaker: Often a 30mA or 300mA dedicated to photovoltaics
4. General circuit breaker: Check that the general power supply to your home is not cut off

Checking procedure:

• All circuit breakers must be in the "ON" (up) position
• If a circuit breaker is in the "OFF" position, try switching it back on
• Warning: If it immediately trips again, this indicates a serious problem - contact a technician
• Then check whether your inverter has restarted

"I thought my installation was down for a whole week. In reality, the circuit breaker had blown after a storm and all I had to do was turn it back on!"

-

Pierre, owner of a 6 kWp installation

Check #4: Monitoring system and connectivity

Most modern installations are equipped with a monitoring system accessible via mobile application or web portal. This is an excellent diagnostic tool that can reveal valuable information.

Points to check :

1. Internet connection: Is your inverter or communication gateway well connected (Wi-Fi or Ethernet)?
2. Application or web portal:
   • Does

the

1. • application connect correctly?
   • Does it display recent data?
   • Are

there

1. • any alerts or error notifications?
   • Does the production displayed match your observations?

2. Production data: Compare with previous days with equivalent weather

Corrective action:

• If connection problem: restart your internet box/Wi-Fi router
• Check your inverter connection cables
• Check the error history in the application

A high-performance monitoring system is essential for the day-to-day management of your production. Discover our energy management and monitoring solutions for better visibility and control of your installation.

Check 5: Visual safety inspection

A visual inspection from the ground can reveal obvious damage. Important: Never climb onto the roof without proper equipment and expertise.

Items to examine (from the ground, with binoculars if necessary) :

1. Panel integrity: Look for cracks, breaks or abnormal dark spots
2. Visible wiring: Check that no cables are hanging or cut
3. Fastenings: Do rails and brackets still appear to be securely fastened?
4. Connectors: Are junction boxes closed and watertight?

In the event of damage :

• Do not attempt any repairs yourself
• Switch off the inverter immediately
• Take photos for your installer or insurer
• Contact a professional without delay

Summary table: quick diagnosis according to symptoms

p

decrease

Need help identifying a specific problem? Contact our technical team for a free telephone pre-diagnosis.

Case study: The Grosjean family's successful diagnosis

The Grosjean family contacted us in a hurry: their 8 kWp installation was producing only 2 kWh per day instead of the usual 25 kWh. Methodically following our checklist:

1. Weather: Sunny day, no visible shading
2. Inverter: Displayed a "String 2 faulty" error code
3. Circuit breakers: All in the correct position
4. Monitoring: Confirmed loss of production from one string of panels
5. Inspection: An MC4 connector had come loose on string 2

Result: After switching off the power supply and replacing the connector correctly, the installation returned to normal production. Savings: €180 in repair costs avoided!

When to call in a professional technician?

Despite these checks, there are still some situations that require the intervention of a qualified professional:

Emergency situations :

• Burning smell or smoke
• Visible sparks
• Repeatedly tripped circuit breaker
• Significant physical

damage

Complex technical problems :

• Persistent error codes after restart
• Unexplained

drop in

• production
• Intermittent

malfunctions

• Grounding problems

When contacting a technician, please provide:

• The make and model of your inverter
• The error codes found
• The results of your 5 checks
• The start date of the problem

This information will ensure a quicker and more efficient response. If you need replacement parts, our team can advise you on which components are compatible with your installation.

"Thanks to Wattuneed's diagnostic advice, I was able to identify the problem and provide the technician with all the relevant information. The intervention was fast and targeted!"

-

Grosjean family, Liège

FAQ : Frequently asked questions about solar failures

My production is low but not zero, is this normal?

Low production is normal on overcast days, short winter days, or early morning/late evening. Compare with your historical monitoring data for similar conditions. An abnormal and persistent drop in production in good weather may indicate a problem.

My inverter is making noise. Should I be worried?

A slight humming noise during production is normal. On the other hand, rattling, hissing or abnormal noises may indicate a problem. Note when these noises occur, and contact a technician if they persist.

Can I clean my panels myself?

Yes, if they are easily accessible from the ground. Use only clear water and a soft brush. Avoid high-pressure cleaners, and never work on a slippery roof or in bad weather.

How much does a repair job cost?

Rates vary: simple diagnosis (€80-120), connector replacement (€150-200), inverter replacement (€500-1500). That's why it's important to carry out your own checks first.

How often should I check my installation?

Check your monitoring at least once a week, and carry out a monthly visual inspection. Annual professional maintenance is recommended to optimize performance and prevent breakdowns.

Conclusion: become autonomous in managing your system

Mastering these 5 essential checks gives you valuable autonomy in managing your photovoltaic system. This proactive approach saves you time and money, while developing a better understanding of your energy system.

Remember that prevention is still the best approach: regular monitoring, minimal servicing and annual preventive maintenance will prevent most breakdowns and optimize performance over the long term.

Keep a logbook of your installation, with monthly production figures, interventions carried out and anomalies noted. This information will be invaluable for future diagnostics.

Your solar system deserves the best support. Discover our complete solutions for optimizing your existing system or planning an extension.

Wattuneed - Your partner for renewable energy
Rue Henripré 12
4821 Andrimont, Belgium
Phone: +32 87 45 00 34
Email : info@wattuneed.com

As a specialist in renewable energy equipment and photovoltaic solutions, Wattuneed can help you install, maintain and optimize your solar systems with expertise and professionalism.