The Ultimate Solar Panel Troubleshooting Checklist

Solar panels are built to last decades, but even the most reliable systems can run into problems. From sudden drops in power output to cracks, hot spots, or inverter malfunctions, knowing how to troubleshoot solar panel issues early can prevent bigger, more expensive repairs.

In this guide, we explain the most common problems, their causes, and practical fixes—so you can keep your solar system producing clean, consistent energy for years to come.

The Most Common Solar Panel Issues and How to Fix Them

Understanding the most common problems with your solar system is half the battle. Each issue has telltale symptoms, specific causes, and proven solutions. 

Let's break down the problems you're most likely to encounter and how you can fix them.

#1. Reduced Power Output

Your monitoring system shows a noticeable drop in energy production compared to previous months or the system's expected performance. This decline can be gradual or sudden.

This is perhaps the most frustrating issue because it can stem from numerous sources, including:

• Dirt and debris accumulation. According to a study, dust buildup can reduce photovoltaic  efficiency by up to 64%, with coal dust being the most detrimental. However, this level of loss typically occurs only in extreme conditions, such as areas with high industrial pollution or minimal cleaning.” 
• Shading. Newly grown tree branches, nearby construction, or even bird droppings can significantly impact solar panel performance. 
• Faulty connections, aging inverters, or problems with individual panels can cause power drops as well.

To fix a solar panel not producing enough power, you need to start with the basics. 

First, you need to clean your panels with mild soap and water. Second, check for any new sources of shade and trim vegetation if necessary. Third, use your system's monitoring app to identify if specific panels are underperforming, which might indicate localized issues rather than system-wide problems.

#2. Cracks or Physical Damage

This issue presents as visible cracks in the glass surface, damaged frames, or panels that appear discolored or have moisture inside the glass layers.

The most probable causes include: 

• Weather events (e.g. hailstorms)
• Thermal expansion and contraction over many seasons 
• Poor installation practices or structural issues with your roof 

Small surface scratches usually don't affect performance significantly, however, deep cracks that penetrate the glass can lead to moisture infiltration and electrical hazards. 

In this case, document any damage with photos and contact a certified solar technician immediately. While most solar panel warranties cover manufacturer defects and performance guarantees, they typically don’t cover physical damage from weather events like hail or storms. In those cases, homeowners may need to rely on their property insurance policy rather than the warranty.

#3. Hot Spots on Panels

If certain areas of your panels feel noticeably warmer than others, or you notice dark spots or discoloration developing on specific cells, then there is an issue you need to address.

This solar panel issue usually happens when individual solar cells become shaded while others remain in full sunlight, or when cells develop electrical resistance issues. Also, debris like leaves or even small amounts of bird droppings can trigger this problem.

To fix this issue, you need to clear any visible obstructions immediately. Hot spots on solar panels can cause permanent damage if left untreated, potentially requiring panel replacement. If hot spots persist after cleaning, professional diagnosis is essential as this might indicate internal electrical problems.

#4. Inverter Problems

In this case, your inverter will display some of the symptoms listed below: 

• Error codes
• Unusual lights
• Unusual sound
• No power despite sunny conditions

Inverter problems in solar systems are relatively common since inverters typically have shorter lifespans than panels—usually 10-15 years. The possible causes of these failures include:

• Overheating
• Electrical surges
• Component wear

To address these issues, first, you need to check for error codes and consult your inverter's manual or manufacturer website for troubleshooting steps. Sometimes a simple reset can resolve temporary glitches. However, most inverter issues require professional attention, especially if they involve electrical component replacement.

#5. Wiring & Connection Issues

These solar panel issues manifest in:

• Intermittent power production
• System shutdowns during certain weather conditions
• Burn marks around connection points

Wiring and connection faults in solar panels can develop from weather exposure, poor initial installation, or pest damage. Consequently, loose connections create resistance, leading to heat buildup and potential fire hazards.

However, fixing these issues is strictly professional work, so never attempt to repair wiring issues yourself. If you notice any signs of damaged wiring, shut off your system immediately and call a qualified solar technician.

#6. PID (Potential Induced Degradation)

PID causes significant losses in power, exceeding 30%, and the symptoms include gradual solar panel efficiency loss across multiple panels, particularly noticeable in monitoring data which show declining performance over months.

This phenomenon occurs when voltage differences between the solar cells and the grounding system cause power losses. Additionally, high temperatures and humidity accelerate this process.

PID often requires professional intervention using specialized equipment to restore panel performance. Some newer panels include PID-resistant designs, but older systems may need component upgrades or circuit modifications.

#7. Weather-Related Issues (Snow, Ice, Hail)

Panels are designed to withstand weather extremes, however, heavy snow can block sunlight entirely, severe hail can cause physical damage, while ice buildup can create electrical hazards.

For snow removal, use a soft brush or wait for natural melting—never use hot water or metal tools. After hailstorms, inspect for cracks or frame damage. Most weather-related issues require patience more than intervention, but severe damage needs professional assessment.

#8. Ground Faults and Arc Faults

In this case, your system's safety mechanisms will trigger shutdowns, or you’ll notice error messages related to electrical faults.

These safety issues can develop from:

• Damaged wiring
• Moisture infiltration
• Component degradation

Ground faults and arc faults are serious safety concerns that require immediate professional attention. These systems are designed to prevent fires and electrocution, so never ignore these warnings.

#9. Monitoring System Failures

Some of the most common symptoms include:

• Monitoring app shows no data
• Displays obviously incorrect readings
• Stops updating entirely

Monitoring system failures are usually caused by:

• Communication hardware failures
• Internet connectivity issues
• Software glitches

First, you need to check your internet connection and router settings. Many monitoring issues resolve with simple reboots of the monitoring hardware. However, hardware failures require professional replacement.

#10. Battery Storage Problems

If your solar battery doesn’t hold charge, drains faster than expected, or fails to power appliances during outages, then you most probably have a battery storage problem. 

This can happen due to several reasons, including:

• Battery degradation
• Poor maintenance
• Extreme temperatures
• Faulty connections 

In some cases, incorrect system sizing leads to batteries being overworked.

To troubleshoot this issue, check your monitoring app for charge/discharge cycles and performance metrics first. Make sure your batteries are kept in a temperature-stable environment, however, if capacity loss continues, consult a professional. Batteries usually require replacement every 5–15 years depending on type and usage.

Common Solar Panel Issues and Efficiency Loss

The table below highlights the most common issues and their impact on performance:

Solar Panel Troubleshooting Checklist

When your system isn't performing as expected, use our troubleshooting checklist before calling a professional:

1. Visual inspection. Walk around your property and examine panels for obvious issues. Look for dirt, debris, shading from new growth, or physical damage like cracks or loose mounting hardware.

2. Performance check. Compare current production data with historical performance. Most monitoring systems let you view daily, monthly, and annual production trends. A sudden drop often indicates a specific event, while gradual decline suggests aging or accumulating issues.

3. Inverter status. Check your inverter for error codes, unusual lights, or displays. Most modern inverters have diagnostic capabilities that can pinpoint problems. Note any error codes for professional consultation.

4. Connection points. Inspect visible wiring and connections for signs of damage, corrosion, or loose connections. Never touch electrical components, but look for obvious problems like damaged cables or burn marks.

5. Environmental factors. Consider recent weather events, nearby construction, or changes to your property that might affect panel performance. Sometimes the solution is as simple as trimming tree branches.

6. System reset. If your monitoring shows communication issues, try resetting your monitoring hardware and checking your internet connection.

Remember to document everything with photos and notes—this information proves invaluable when working with technicians or warranty claims.

When to Call a Professional vs. DIY Fixes

The line between safe DIY maintenance and professional intervention isn't always clear, but with our practical guide, it will be easier for you to decide.

The following table shows when to ask for professional and when it’s safe to do it yourself:

Keep in mind that many solar panels and system components come with extensive warranties, and DIY repairs can void these protections. Before attempting any fixes beyond basic cleaning, check your warranty terms. Sometimes it's worth paying for professional service to maintain warranty coverage.

At Portable Sun, we maintain a network of certified installers and technicians who understand the complexities of modern solar systems. When in doubt, professional consultation often saves money compared to trial-and-error repairs.

Final Thoughts

Solar panel troubleshooting doesn't have to be intimidating when you understand the common issues and their solutions. Most problems have straightforward fixes, and regular maintenance prevents many issues from developing in the first place. The key is recognizing what you can safely handle yourself versus when professional help is necessary. 

By staying proactive with regular cleaning and monitoring your system's performance, you'll catch problems early and keep your investment generating clean energy for decades. Remember, a well-maintained solar system isn't just about maximizing energy production—it's about protecting the long-term value of your renewable energy investment.

Solar Panel Issues & Troubleshooting FAQ

#1. What is the 33% rule in solar panels?

The 33% rule refers to the maximum amount of shading a solar panel can tolerate before performance drops significantly. When more than one-third of a panel is shaded, power output decreases disproportionately due to the series connection of solar cells within the panel.

#2. How to reset a solar panel?

Solar panels themselves don't reset, but you can reset the inverter by switching off the DC disconnect, waiting 30 seconds, then switching it back on. For monitoring systems, unplug the communication device for 10 seconds and reconnect it to restore data transmission.

#3. What is a common defect on a solar panel?

Micro-cracks are among the most common defects, often invisible to the naked eye but detectable through thermal imaging. These hairline fractures can develop during manufacturing, shipping, or installation and may worsen over time, reducing panel efficiency gradually.

#4. How to check if my solar panels are working properly?

Monitor your system's daily energy production through your inverter or monitoring app, comparing it to historical data and weather conditions. A properly functioning system should produce consistent power relative to sunlight availability, with only gradual efficiency decline over many years.