Checks you can do safely
Before calling anyone, these checks narrow the problem down and cost nothing. None of them involves opening equipment or going on the roof.
- Rule out the weather. Compare with the same week last year in the app. Clouds, snow on the panels and short winter days explain most drops.
- Check whether data is missing or production is low. If the app stopped updating but the inverter display shows it is producing, the problem is usually the Wi-Fi connection, not the system.
- See how much is affected. If the whole system reads zero, the cause is usually the inverter, a breaker or a grid outage. If some panels read low, it is usually shade, dirt or a single failed microinverter or optimizer.
- Read the inverter. Note the status light and any error code on the display or in the app.
- Check the breakers. Look for a tripped solar breaker in the main panel and check the solar disconnect near the meter. Reset a tripped breaker once; if it trips again, leave it off and call a technician.
- Look from the ground for new shade from trees, heavy dirt, droppings or visible damage.
If none of that explains it, the next steps need a technician.
Which equipment you probably have
Knowing your inverter type narrows down most problems. In public installation records for home systems installed in 2023–2025 (Tracking the Sun):
| Inverter brand | Share of systems | How a failure usually shows up |
|---|---|---|
| Enphase | 48% | A microinverter sits under each panel. One failure usually takes out a single panel, and the Enphase app shows which one. |
| SolarEdge | 27% | One central inverter on the wall, with an optimizer under each panel. If the inverter fails, the whole system stops; its display or the app shows an error code. |
| SunPower | 4% | Most of these use microinverters under each panel. SunPower filed for bankruptcy in 2024, so check who now handles monitoring and warranty service. |
| Tesla | 14% | One central inverter (or a Powerwall 3 with a built-in inverter). Errors appear in the Tesla app. |
If the whole system reads zero, start with the inverter and the solar breaker. If production dropped gradually, look at shade, dirt and individual panels in the monitoring app.
What a technician tests next
- Monitoring data: when the problem started and whether it affects the whole system or specific panels.
- Inverter logs: stored error codes, often read with the manufacturer’s tools.
- Visual inspection: damaged panels, chewed wires, burnt connectors and signs of heat.
- Electrical tests: voltage, current and insulation resistance on each string of panels to find where the fault is.
- Isolation: disconnecting parts of the system one at a time until the fault is found.
- Estimate: what failed, what the repair costs, and what a manufacturer’s warranty covers.
Cost factors
| Factor | Impact on cost |
|---|---|
| Type of problem | A tripped breaker is quick; an intermittent ground fault can take hours. |
| Access | Steep roofs or panels that have to be lifted to reach the wiring add time. |
| System age | Parts for older or discontinued equipment can be hard to find. |
| Warranty | A covered inverter or microinverter is replaced free, but labor may not be covered. |
When to call a technician
- The whole system is at zero on a sunny day and the breaker isn’t tripped.
- The same error code keeps coming back after the inverter restarts.
- The solar breaker trips again after you reset it.
- Production stays low compared with the same month last year, and shade and dirt don’t explain it.
- A buzzing, clicking or burning smell comes from the inverter. Turn the system off and call right away.
Questions to ask your provider
- Do you work on my inverter and panel brands?
- What is the diagnostic fee, and does it count toward the repair?
- Will you give me a written estimate before doing any repair?
- Are your technicians NABCEP-certified or licensed electricians?
- Will you file the warranty claim with the manufacturer if a part has failed?
- How long do you guarantee the repair?
What to watch out for
- Opening equipment yourself. Inverters, junction boxes and array wiring can carry dangerous DC voltage in daylight, even with the breaker off.
- Assuming it will fix itself. An inverter that keeps restarting, or a breaker that keeps tripping, is a sign of a real fault.
- Pushing a full replacement before the fault is found. Most problems are one inverter, one panel or one connector.
- Paying for parts under warranty. Check the manufacturer’s warranty before paying for a replacement inverter or microinverter, even if your installer has closed.