Last updated: March 23, 2026
Before you start: Solar systems carry high DC voltage at all times — including on cloudy days and at night. Everything in this guide involves your monitoring app, visible inspection from ground level, and breaker positions only. Do not open any equipment enclosures, access roof-mounted components, or touch wiring. Those steps require a licensed solar technician.
First, identify your situation. The cause — and the fix — is different for each one.
Most solar panels work for years without needing much attention. When something does go wrong — or seems to go wrong — the symptom is almost always the same: the numbers on your monitoring app don’t look right. What that actually means, though, depends entirely on which of the three situations above you’re in.
This guide helps you identify your situation, understand the most likely causes, and know exactly what to check before calling your installer. It also tells you when a professional is the right call from the start — because some situations look like user-fixable problems but aren’t.
Your System Is Showing Zero Production
Zero production from your monitoring app is alarming, but it doesn’t always mean something is broken. The first thing to establish is whether the system is actually not producing, or whether the monitoring app has simply lost its connection to the system.
These are different problems with different solutions — and the monitoring glitch is far more common than an actual system failure.
Step 1: Check whether it’s a monitoring issue first
Open your monitoring app and look for a connectivity or communication error — not just a production number. A disconnected inverter shows zero production even if the panels are working fine. Common signs of a monitoring glitch rather than a real failure:
- Production shows zero but the app shows the last update was days or weeks ago
- The app shows a Wi-Fi or communication error alongside the zero reading
- Production was normal recently and stopped showing data suddenly without any weather event
If you see a communication error: restart your home router, wait five minutes, and check whether the production data resumes. Many “failures” resolve at this step.
Step 2: Check the solar breaker in your main electrical panel
Your solar system connects to your home through a dedicated breaker in your main panel — typically labeled “Solar,” “PV,” or “Photovoltaic.” A tripped breaker cuts the system completely and shows as zero production.
Locate your main panel (usually in a utility room, garage, or outside). Look for a breaker that is in the middle position rather than fully on or fully off — that’s a tripped breaker. Flip it fully off, then back on.
If the breaker trips again immediately: Do not reset it a second time. A breaker that trips repeatedly indicates a fault in the system that needs professional diagnosis. Leave it off and contact your installer.
Step 3: Check the inverter display
Walk to your inverter — for most residential systems, this is a box mounted on a wall near your main panel, in the garage, or on an exterior wall. Look at the indicator light or display screen without opening the enclosure:
- Green light or “Normal” / “Producing”: The inverter is operating — the issue is upstream (monitoring, breaker) not the inverter itself
- Red or orange light / error code: The inverter has detected a fault and shut down
- No light, no display: The inverter has no power — check the breaker first
If you see an error code: write it down exactly. Look up your inverter model number (printed on the label on the enclosure) and the error code together. Manufacturer documentation explains what each code means. Bring this information when you call your installer.
Stop here. Do not open the inverter enclosure. Do not attempt to reset the inverter by accessing internal components. Error codes that indicate hardware faults — overtemperature, insulation failure, grid fault — require a licensed technician. Opening the enclosure may also void your warranty.
One important note about anti-islanding
Grid-tied solar systems are required to shut down automatically when the utility grid goes down — this is a safety feature called anti-islanding protection, designed to protect utility workers on power lines. If your neighborhood has lost power, your solar system will show zero production even if everything is working perfectly. Production resumes automatically when grid power is restored. Check your neighbors before assuming a system problem.
Your System Is Producing Less Than Usual
Reduced production — not zero, just lower than expected — is the most common concern solar owners report. It’s also the most frequently misdiagnosed, because most cases have a completely normal explanation.
Before assuming something is wrong, compare your current production against the right benchmark. Same month, last year — not last month. Solar output varies by 40–60% between seasons in most U.S. locations. Comparing February to December is not a useful comparison.
Normal causes — no action needed
Seasonal variation. Your system produces significantly more in summer than winter because of longer daylight hours and higher sun angles. This is expected and is factored into your installer’s annual estimate. A system running perfectly in January will produce roughly half what it produces in July in most Northern states.
Weather. Overcast days reduce output by 10–25% for light cloud cover and up to 90% on heavily overcast days. A cloudy week will show a clear production dip in your monitoring history.
Temperature. Counterintuitively, very hot days slightly reduce panel efficiency. Solar panels are tested at 25°C — for every degree above that, most panels lose approximately 0.3–0.5% of output. A 40°C summer day reduces output by roughly 4–7% compared to ideal conditions. This is normal and is built into system estimates.
Natural panel degradation. According to NREL, residential solar panels typically degrade at about 0.75% per year. A 10-year-old system should produce approximately 92–93% of what it produced when new. Gradual, consistent decline over years is normal.
Causes worth investigating
New or increased shading. Shading is one of the most impactful and commonly overlooked causes of production loss. A tree that grew taller, a new neighbor’s structure, or seasonal changes in sun angle can cast shade that didn’t exist when your system was installed. Even partial shade on one panel can reduce output across an entire string in systems without panel-level power electronics.
Check from the ground: look at your panels during peak production hours (roughly 10am–2pm) for shadows falling on any portion of the array. Check on a clear day, not a cloudy one.
Soiling — dirt, dust, pollen, or bird droppings. Panels generally clean themselves during rain, but extended dry periods or heavy pollen seasons can reduce output by 15–25% (Tongwei / industry studies). Look at the panels from the ground. If they appear visibly dirty or have distinct soiling patterns, cleaning may restore output. Do not attempt to clean panels yourself by climbing onto the roof — contact a professional panel cleaning service.
A single panel or microinverter underperforming. If you have panel-level monitoring, check whether one specific panel is consistently showing low or zero output while others are normal. This indicates a single panel defect, a failed microinverter, or a shading issue on that panel specifically.
Your System Has Never Matched What the Installer Estimated
This is a different category entirely from an equipment failure. A system that has always produced less than the installer’s projection is typically a design, shading, or estimation issue — not a broken component.
Before concluding your system is underperforming, understand how installer estimates work. Production estimates are generated using solar modeling software that accounts for your location, roof angle, system size, and shading — but they assume clear, unobstructed conditions that real-world sites don’t always match. The estimate is a projection, not a guarantee.
That said, there are legitimate cases where a system was designed poorly, installed incorrectly, or sold based on unrealistic projections. Signs that a real problem may exist:
- Your actual annual production is more than 15–20% below the installer’s estimate
- Neighbors with similar system sizes and roof orientations are reporting significantly higher production
- Your installer’s estimate assumed shading conditions that don’t match your actual site
- System was installed and issues were reported to the installer who hasn’t resolved them
When to Call Your Installer — Specific Triggers
Don’t wait if any of these are true:
- Zero production that persists after checking the breaker and monitoring connection
- An error code showing on the inverter display
- A breaker that trips more than once
- Visible physical damage to panels, wiring, or the inverter enclosure
- Any burning smell near the inverter or electrical panel
- Production dropped more than 25% compared to the same period last year without a weather explanation
What to tell your installer when you call
Gathering this information before you call saves time and helps your installer diagnose the problem faster — often over the phone rather than requiring a site visit:
- Your inverter make, model, and serial number (on the label on the enclosure)
- The exact error code showing on the display, if any
- Date when you first noticed the issue
- Whether it’s zero production or reduced production
- A screenshot of your monitoring app showing recent production history
- Whether the solar breaker was tripped when you checked
- Any recent events: storms, power outages, tree trimming, roof work
A Note on Warranties
Most residential solar systems come with separate warranties covering the panels (typically 25 years for product and performance), the inverter (5–25 years depending on type — string inverters shorter, microinverters longer), and the installer’s workmanship (typically 5–10 years). Inverter replacement during the warranty period is generally covered for parts, though labor coverage varies by manufacturer and contract.
Unauthorized access to any equipment — opening inverter enclosures, modifying wiring, attempting DIY repairs — typically voids manufacturer warranties. If your system is within warranty, this makes professional service not just safer but financially the right choice.
Common Questions
How do I know if my solar panels are working correctly?
The most reliable way is to check your monitoring app and compare current production to the same period last year — not last month. A system working correctly will show predictable seasonal patterns. Consistent production that matches prior-year data for the same month is a healthy system. If you don’t have a year of prior data, compare your output to your installer’s monthly production estimates.
How much production loss is normal over time?
NREL research places average residential panel degradation at approximately 0.75% per year. A system installed 10 years ago should produce about 92–93% of its original output. A 20-year-old system should produce about 85%. Degradation faster than this — especially if sudden — warrants investigation.
Can I clean my solar panels myself?
Ground-level cleaning using a hose may be possible for single-story installations with accessible panels — use plain water, not pressure washers or soap, which can leave residue that reduces output. For panels on a second story or steep pitch, contact a professional panel cleaning service. Never climb onto your roof to clean panels.
My installer said my system would produce X kilowatt-hours per year. It’s producing less. What do I do?
First establish whether the shortfall is consistent year over year or seasonal. If your annual production is consistently 15–20% or more below the estimate, review your contract for a production guarantee. If one was included, contact your installer in writing with your monitoring data.
Is it safe to keep using my home if my solar system shows an error?
In most cases, yes — your home continues to receive grid power normally when solar isn’t producing. However, if you notice any burning smell, visible smoke, or physical damage to the inverter or wiring, treat it as an electrical emergency and contact your utility and installer immediately.
Sources & Data References
- NREL, Residential PV Annual Technology Baseline 2024 — panel degradation rate 0.75%/yr baseline
- kWh Analytics — 80% of solar array failures occur at inverter level
- Bern University of Applied Sciences (Bucher, Wandel, Joss 2022) via pv magazine — 34.3% residential inverter failure rate within 15 years
- EnergySage — string inverter lifespan 10–15 years, microinverter lifespan up to 25 years
- EnergySage, Solar panel repair and maintenance guide (updated August 2025)
- pv magazine USA, “How long do residential solar inverters last?” (August 2025)