Solar Inverter Error Codes – What They Mean and How to Fix Them

TL;DR: Solar inverter error codes mean the inverter has shut itself down to protect your home, the equipment, or the grid — it does not automatically mean your system is damaged. Most codes fall into a handful of families: grid and utility faults, arc faults, ground or isolation faults, DC overvoltage, overheating, and internal hardware faults. You can safely check the AC breaker, the DC switch position, the monitoring app, and any water ingress yourself. Anything pointing to an arc fault, a ground fault, or a hardware error needs your installer. A diagnostic visit usually runs $150–$400, and a replacement string inverter typically costs $1,500–$3,500 installed.

Few things are more annoying than glancing at your solar app and finding a red warning where your production numbers should be. The good news: inverters are built to fail loudly. When something is off, they stop producing and display or report a code instead of quietly pushing power into your home.

Here is how to read the most common solar inverter error codes, what you can safely fix yourself, and when it is time to call someone.

Why Your Inverter Shows an Error Code

Your inverter sits between two very different worlds: the DC electricity coming off your panels, and the AC electricity your home and the grid use. It constantly checks voltage, frequency, insulation, temperature, and grounding on both sides. If any reading drifts outside the safe range, the inverter disconnects. That behavior is required by safety standards — it protects electricians working on the grid and prevents fire hazards in your wiring.

So an error code is usually a symptom, not the disease. The job is to figure out which family the code belongs to.

The Main Families of Solar Inverter Error Codes

Every brand uses its own numbering, so “code 08” only means something in the context of your specific inverter. What you can rely on is the wording, because almost all faults fall into these groups.

Error family	Typical message	What it usually means	Who fixes it
Grid / utility fault	Grid Fault, Utility Loss, AC Voltage Out of Range, Frequency Fault	The grid voltage or frequency moved outside the allowed range, or the power is out in your area	Wait for the grid, or your utility
Arc fault	Arc Fault Detected, DC Arc Fault	A small electrical arc on the DC side, often a loose or corroded connector	Installer, promptly
Ground / isolation fault	Ground Fault, Isolation Fault, RISO Low	Moisture or damage letting current leak to ground, often after heavy rain	Installer
DC overvoltage	DC Input Overvoltage, PV Voltage Too High	String voltage rose above the inverter limit, often on a cold sunny morning	Installer
Over-temperature	Over Temperature, Temp Fault, Derating	The unit is too hot, usually from blocked airflow or direct sun	You, sometimes
Internal / hardware	Internal Error, Hardware Fault, Relay Fault	A component inside the inverter failed	Installer, warranty claim

What You Can Safely Check Yourself

Before you call anyone, work through this list. It solves more cases than you would expect, and it gives your installer useful information if you do need help.

• Look at the monitoring app first. Note the exact wording of the fault and when it started. A code that appears every night and clears at sunrise is usually not a fault at all.
• Check whether the power is actually out. Grid faults are often just a neighbourhood outage. If your clocks reset, that tells you the story.
• Check the AC breaker. Find the dedicated solar breaker in your main panel. If it is tripped, reset it once. If it trips again, stop and call your installer.
• Check the DC switch on the inverter. It should normally be in the ON position. Someone may have turned it off during service work.
• Look for water or debris. A unit mounted where rain blows in, or sitting under a gutter downspout, will throw ground faults until it dries out. Clear leaves and dust from the vents.
• Check the shade and airflow. Inverters mounted in full afternoon sun on a hot wall survive, but they derate. Shading the unit and clearing its vents can fix temperature faults outright.
• Restart it the way the manual says. Different brands require different shutdown and startup orders, and doing it out of sequence can delay recovery. Follow your brand’s steps exactly.
• Check for firmware updates. Some models ship with firmware that generates nuisance faults, later corrected.

What You Should Never Do

This part matters more than the troubleshooting.

• Never open the inverter casing. It holds lethal DC and stored energy even after it stops producing.
• Never unplug or disconnect DC cables. DC arcs do not self-extinguish the way AC arcs do, which is why DC connectors are not meant to be separated under load.
• Do not assume your panels are safe just because the sun is down. Modules produce voltage whenever there is daylight, and you cannot switch them off.
• Do not clear a serious fault over and over. Repeatedly resetting an arc fault or ground fault to make it go away is how small problems become fires or failed inspections.
• Do not climb onto the roof to inspect cabling yourself. That is what warranties and insurance premiums are for.

When to Call Your Installer

Call the company that installed the system if you see any of the following:

• An arc fault or ground fault message, at any time
• A fault that returns within a day of restarting
• An internal or hardware error
• Burn marks, a hot smell, melted plastic, or crackling sounds
• Any sign of water inside the enclosure
• A code you cannot identify after checking the manual and the manufacturer’s support page

Have the exact code text, the model and serial number, the date the fault started, and your monitoring history ready. Installers resolve cases far faster when the first call includes that information, and it also makes the warranty claim process smoother.

What It Costs

Most residential inverter faults are diagnosed and repaired for far less than homeowners fear:

• Diagnostic or service visit: $150–$400
• Re-terminating or replacing DC connectors: $200–$500
• Ground fault repair from water ingress: $300–$800
• Replacement string inverter, installed: $1,500–$3,500
• Single microinverter replacement, installed: $250–$600

Check your warranty before approving any invoice. Most string inverters carry a 10–12 year warranty and most microinverters carry a 25 year warranty, so a hardware failure inside that window is normally covered, with labour covered depending on your installer’s terms.

How to Prevent Error Codes

• Keep the inverter’s vents clear and shaded from harsh afternoon sun
• After any severe storm, hail, or wind event, check the app and look for visible damage
• Ask for DC connector inspection during routine maintenance — loose connectors cause a large share of arc and ground faults
• Rodent-proof exposed conduit runs, since chewed cable is a classic ground fault source
• Keep the firmware current and check your production numbers once a month, so a slow decline never hides behind a busy week

FAQ

Is it normal for my inverter to show a message at night?

Yes. Many inverters display “waiting,” “standby,” or “night” once the sun goes down. That is normal shutdown behavior, not a fault.

Can I just reset my inverter and ignore the code?

For a one-off grid fault, restarting is reasonable. For anything involving an arc fault, a ground fault, or a hardware error, resetting without finding the cause is risky and can void your warranty.

Is a grid fault my problem or the utility’s?

Usually neither. The inverter is reacting to voltage or frequency conditions it cannot control. If the fault clears on its own, nothing needs fixing. If it happens daily, your installer can log the readings and discuss them with your utility.

Will an error code void my warranty?

No. A fault is a warranty event, not a violation of it. What can affect coverage is unqualified work, such as opening the unit or rewiring DC circuits yourself.

How long can my system stay offline?

Technically as long as you like, but every day offline is lost production. Under reasonable assumptions, a week of downtime on a mid-size system costs roughly $30–$80 in missed savings.

Why did my inverter die right after a storm?

Two common reasons: moisture entering the enclosure or a connector, and surge damage from nearby lightning. Both are worth checking against your homeowner’s insurance policy, since they may be covered separately from the equipment warranty.

How do I read a solar inverter error code if my brand is not listed online?

Search the exact wording displayed on the screen rather than the number, and check the manufacturer’s official support page. The wording is far more consistent across models than the numbering.

Bottom Line

Solar inverter error codes are your equipment telling you something specific, and in most cases the fix is inexpensive. Read the exact message, run the safe checks above, and hand the rest to your installer with the details they need. Whatever you do, resist the temptation to reset and forget — arc and ground faults are the two families that punish guesswork.

Related: Common Solar Panel Problems and How tsolar inverter error codeso Fix Them