Solar System Checklist: What to Do When Something Goes Wrong
Solar power systems are remarkably reliable—often running quietly for 20–25+ years with minimal intervention. But when production suddenly drops, the inverter flashes errors, or your system stops working altogether, it can feel alarming. The good news? Most issues are straightforward to diagnose with a logical, step-by-step approach.
This practical troubleshooting checklist helps homeowners quickly identify the most common culprits behind solar system problems, from zero output to mysteriously low performance. Always put safety first: if you're uncomfortable working with electrical components or high DC voltages, stop and call a certified solar technician.
Step 1: Confirm There's Actually a Problem
Before diving in, verify the issue isn't environmental, temporary and everything is switched on.
- Check your monitoring app/platform (Enphase Enlighten, SolarEdge Monitoring, etc.) → What does current production look like compared to yesterday/same time last week?
- Compare against expected output → Use PVWatts (NREL tool) or your installer's production estimate for your location, system size, and today's weather.
- Rule out obvious weather → Heavy clouds, rain, snow cover, or very short winter days can cut output dramatically (but shouldn't cause complete failure).
If production is zero or far below expectations on a clear day → proceed to the checklist.
Step 2: Quick Safety & Visual Inspection (No Tools Needed)
Start with the easiest, safest checks
Look at the inverter display/lights
- No lights or screen dead? → Possible tripped breaker, power supply issue, or inverter failure.
- Red/error lights or specific codes? → Note the exact code/message (Google "[brand] error code [number]").
- Normal but no production? → Keep going.
Check your home's electrical panel & solar sub-panel
- Look for tripped breakers or blown fuses labeled "Solar," "PV," "Inverter," or similar.
- Reset any tripped breakers (once only—if it trips again immediately, stop and call a pro).
Inspect panels from the ground (binoculars help)
- Obvious shading? New tree growth, antenna, chimney shadow, or even a single branch can kill output on string systems.
- Dirt buildup, bird droppings, leaves, or pollen layer? Heavy soiling can cut production 10–30%.
- Visible cracks, burn marks, delamination, or discoloration?
Look around the array
- Animal nests/damage (squirrels, rats, birds love chewing wires)?
- Loose hanging wires or obvious disconnected MC4 connectors?
Step 3: Basic Cleaning & Minor Fixes Homeowners Can Safely Do
Clean the panels (early morning or late afternoon to avoid thermal shock)
- Use soft brush + hose or distilled water + mild soap. Never use abrasive tools.
- Many "low production" complaints disappear after cleaning.
Clear shading
- Trim branches or move portable objects. Even partial shade on one panel can drag down a whole string.
Power cycle the system
- Turn off the main solar breaker → wait 5 minutes → turn back on.
- Many inverters reset minor glitches this way.
Step 4: Mid-Level Checks (Multimeter Helpful – Proceed with Caution)
If the basics don't solve it:
String / array level issues (common on string inverters)
- One underperforming string can pull the whole system down.
- Look for hot spots, darker panels, or obvious damage.
Loose connections / corrosion
- MC4 connectors can work loose over time → gentle wiggle test (system off!).
- Look for green corrosion or burn marks.
Inverter specific
- Overheating → Ensure vents are clear, no dust buildup.
- Fan not running (on models with fans)?
- Capacitor swelling or odd smells?
Battery system extras (if you have storage)
- Low SOC, uneven cell voltages, BMS errors, poor airflow around batteries.
Step 5: When to Call a Professional (Immediately)
Stop DIY troubleshooting and contact your installer or a qualified solar electrician if:
- Tripped breaker keeps tripping
- Burning smell, smoke, or arcing visible
- Inverter shows ground fault (GFI), insulation resistance (ISO/RISO), or arc fault (AFCI) errors
- System completely dead after power cycle + breaker check
- Suspected panel hotspot or cracked/burned modules
- Production drop >30–40% that persists after cleaning/no shading
- Any battery-related swelling, leaking, or extreme heat
These can indicate serious safety risks (fire, shock) or warranty-covered failures.
Prevention: Stop Tomorrow's Headache Today
A 5-minute monthly glance prevents 80% of issues:
- Monitor production weekly
- Keep panels clean (2–4× per year in dusty/pollinated areas)
- Trim vegetation before it shades
- Check inverter vents/fans seasonally
- Torque-check connections (pro recommended) every 1–2 years
Most solar problems are simple—dirt, shade, a tripped breaker, or inverter glitch. By following this checklist methodically, you'll either fix it yourself or gather exactly the info a technician needs to resolve it fast.
Your solar system is still one of the best home investments you'll ever make. A little proactive troubleshooting keeps those electrons flowing cleanly for decades.
*Stay safe, and enjoy the sunshine savings!* ☀️