How often should you check your solar panels?

A failed string, a fault code or a pigeon nest can cut output for months before anyone notices on the bill.

A system producing half its expected output loses its payback quietly. Loose cabling and animal damage under the panels are also fire and water ingress risks on the roof.

1. Compare this year’s output with last year’s. Open the inverter or monitoring app and compare the same months. A drop of more than about 10 percent with similar weather is worth a call to the installer.
2. Check the inverter. Look for fault codes or warning lights, and make sure the vents are clear of dust and stored items.
3. Look at the panels from the ground. Use binoculars if needed. Look for cracked glass, heavy soiling, leaves collecting at the bottom edge and signs of birds nesting underneath.
4. Check the visible cabling and isolators. Cables should be clipped, not hanging or chewed. Do not open isolator boxes or disconnect anything under load.
5. Clean only if needed, and only from the ground. Rain cleans most panels. Where cleaning helps, use a soft brush on a pole and plain water. No pressure washers, no detergents, no climbing on the roof.

• Monthly output lower than the same month last year
• An inverter warning light or fault code
• Visible bird nesting or debris under the panels

• Climbing onto the roof to clean panels
• Using a pressure washer or detergent, which can damage seals and void warranties
• Ignoring a monitoring app that has silently stopped reporting

For any fault code that returns after a restart, damaged glass, scorch marks, or cabling problems. Panel and inverter work is for the installer or a qualified electrician.