When a solar inverter stops working, the cause is often outside the box: a tripped breaker, a grid outage, heat, or lost monitoring. Start with the safe checks below, write down the code or light, and call a technician if it is a fault.
Why the inverter is the first thing to check
Your panels make DC power. The inverter turns it into the AC power your home and the grid use. If the inverter stops, the whole system stops, even on a perfect sunny day.
It is also the part that fails most often. A study of solar maintenance records led by NREL describes inverters as a leading source of hardware failures and energy losses at PV sites. So when production drops, the inverter is the right place to start looking.
The good news: a dark or red inverter does not always mean a broken one. Many shutdowns are the inverter protecting itself or the grid, and they clear on their own once the cause is gone.
What the lights and alerts usually mean
- String inverter, green light blinking: On SolarEdge units, a blinking green light usually means AC is connected but the system is not producing, often because the optimizers are not paired, per this SolarEdge LED guide.
- String inverter, solid red light: On the same SolarEdge units, a solid red light means there is an active system error. The screen or app will show a code. Write it down before you do anything else.
- Microinverter, flashing red: On Enphase microinverters, flashing red generally means the unit is not producing because it does not see the grid within spec, per the Enphase manual. Check for an outage or a tripped breaker first.
- Microinverter, solid red: A solid red light on many Enphase models points to a DC fault, such as a ground or insulation problem, per the IQ8 status LED table. That one needs a technician, not a reset.
- Tesla inverter, not producing: Tesla's own troubleshooting page says to follow the alert steps in the app first and contact support if the issue stays.
Safe checks you can do today
- Confirm the grid is on. Do your lights and outlets work? Check your utility's outage map. With no grid, a grid-tied inverter is supposed to sit dark.
- Open your monitoring app. Look at the last day it produced normally. A sudden drop to zero points to a shutdown. A slow slide over months points to something else, like shading, dirt, or a failing part.
- Read the inverter screen or light. Take a photo of the screen, the light color, and the label with the model and serial number. A technician can often narrow the problem from that photo alone.
- Check the solar breaker. In your main electrical panel, find the breaker labeled solar or PV. If it is tripped, switch it fully off, then on, once. If it trips again, leave it off and call.
- Do one restart, by the manual. Most inverters have a shutdown and startup order in the manual. Follow it once. Many units take several minutes to come back while they check the grid.
- Look at the panels from the ground. New shade from a tree, heavy debris, or a panel that looks out of place after a storm can all cut output. Do not climb on the roof to check.
What not to touch
- Do not open the inverter cover or any junction box. There can be live voltage inside even when the screen is off.
- Do not unplug or pull apart roof wiring. Panels make DC power whenever the sun is up, unless the system is built to drop that voltage at shutdown, as SolarEdge systems are designed to do.
- Do not keep flipping the breaker. A breaker that trips again is telling you something. Repeated resets can make a fault worse.
- Do not let a general handyman or roofer work on it. Wrong work can void equipment warranties, as we explain in what happens when unlicensed crews touch your system.
- Do not spray water on hot panels or the inverter to cool them down.
Outages and Texas heat: when off is normal
Grid-tied inverters are required to shut down when the grid goes down, so they do not send power onto lines that crews think are dead, as this outage explainer covers. Without a battery, your home loses power too. If outages are your real worry, read about how to add a battery to your existing solar system.
Heat is the other big one in Texas and Florida. Inverters reduce their output on purpose when it gets too hot, to protect their parts. SolarEdge calls this derating and lists the temperature limits for each model in its temperature derating note. Output comes back as the unit cools.
A simple test: if output drops only on the hottest afternoons, it is likely heat. If it collapses on a mild, sunny day, that points to a fault, as Solar Power World notes. An inverter in direct afternoon sun, or in a closed garage with no airflow, will run hotter.
When to stop and call a technician
- Zero output on a clear, mild day: Grid is on, breaker is on, and the system still shows nothing. That is a fault, not the weather.
- The same error keeps coming back: A code that clears and returns after a restart usually means a real problem in the inverter, the wiring, or a panel.
- A ground or insulation fault: Any code or light that points to a DC, ground, or isolation fault. These involve high voltage and need testing with proper meters.
- Burning smell, buzzing, or heat damage: Shut the system down by the manual and call. Do not wait for the next sunny day to see if it fixes itself.
- After a storm or roof work: Hail, wind, or a roofer moving panels can damage connectors and wiring you cannot see from the ground.
Repair, replace, or upgrade?
Inverters wear out faster than panels. The U.S. Department of Energy notes that inverter degradation drastically limits its lifetime, which leads to part replacements over the life of a system. Plan on the inverter needing attention before the panels do.
Before you pay for anything, find your warranty papers. Many inverter warranties are handled by the manufacturer, not the installer. If the company that installed your system has closed, you still have options. Our guide on what to do when your solar company went out of business walks through it, and our project rescue team takes on systems other companies left behind.
If you are replacing the roof soon, that is a smart time to look at the inverter too. See when to upgrade your inverter during solar panel removal. And if the inverter works but your bill still went up, the problem may be the rate plan, not the equipment. Start with why your solar panels are not saving money anymore.
The Light Group USA has licensed and insured technicians who diagnose and repair solar systems, including ones installed by other companies, across Texas and Florida. Call (844) 440-7322 or request an inspection.
Frequently Asked Questions
The most common reasons are a grid outage, a tripped solar breaker, or the inverter waiting to confirm the grid is stable after a restart, which can take several minutes. If the grid is on, the breaker is on, and the screen stays dark or shows a fault after one restart by the manual, call a technician.
Yes, once, by following the shutdown and startup order in your inverter's manual. Turning the solar breaker off and on is usually part of that order. Do not open the inverter or touch the wiring. If the same error comes back, stop resetting and have the system checked.
On very hot days, inverters reduce output on purpose to protect their parts, which is called derating. Output returns as the unit cools. If it stops completely on mild days too, or shows an error code, it is more likely a fault than heat.
A standard grid-tied system without a battery shuts down during an outage. That is a safety rule, so power is not sent onto lines that utility crews are working on. To keep power during outages, you need a battery and equipment set up for backup.
