Is it safe to leave an inverter showing a red light?

In most cases, yes — the inverter has shut itself down as a protection measure, which is the correct response. It is not exporting or drawing current in a faulted state. Do not attempt to repeatedly reset it as this can damage the equipment and masks the underlying problem. It is not safe to leave a system in a faulted state for extended periods — arrange a diagnostic within a reasonable timeframe.

My inverter red light appeared during heavy rain — why?

Rain can trigger isolation fault (earth leakage) trips. Water ingress into a junction box, connector, or cable conduit creates a small leakage current between the live DC circuit and earth. The inverter's isolation monitoring detects this and trips as a safety measure. The fault often clears when the system dries out, but the underlying ingress point must be found and sealed to prevent recurrence.

Inverter fault · All brands

Red light on your solar inverter

Q: What does a red light on a solar inverter mean?

A red light on a solar inverter indicates a fault condition — the inverter has detected something outside its operating parameters and has shut down to protect itself and the grid. The specific cause varies widely: grid overvoltage, arc fault detection, isolation failure, DC overcurrent, battery communication fault, or overheating are all common triggers. The fault code on the display or in the portal event log identifies the exact cause.

Q: Can I reset my inverter if it shows a red light?

A single controlled reset is reasonable for certain fault types — particularly grid-related faults that may have been caused by a momentary grid disturbance. Turn off AC and DC isolation, wait 5 minutes, turn back on. If the fault returns within a few minutes of resetting, do not reset again. Repeated resets can damage the inverter and will not resolve a persistent fault.

A red fault light means the inverter has detected something outside its safe operating range and shut down. It is a protection mechanism — but it still needs diagnosing. The cause could be a momentary grid event that has already resolved, or an ongoing fault that will prevent generation until it's fixed.

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Red light = protection trip, not failure
Fault code tells you the cause
Do not repeatedly reset

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A remote diagnostic session interprets the fault code in context — event log history, grid voltage data, system configuration — and gives you a clear cause and fix route.

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Safety: if you smell burning, see arcing or physical damage, isolate at the consumer unit immediately and do not restart.

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A superb service from Ron who went beyond the normal service received from other Tech support companies. I live abroad and was badly let down when my givenergy system failed (and the company went bankrupt) and the local supplier ran away from the problem. Ron sorted the problem and even accessed specialist coding for the inverter that would not be available for suppliers. Ron also ran a full diagnostic to insure that all was in good working order afterwards. Without Rons support and patient assistance I doubt I would ever have got the system back up and running. Well done and thankyou and you have a customer for the future.

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When my GivEnergy system had an issue, I was completely left without support and had honestly lost all hope. Thankfully, I searched online and found Ron, which completely turned things around. After sending him a message, he responded incredibly fast and called me to assure me that he would get the problem fixed. I really admire his dedicated, supportive nature and his determination to find a solution. With this kind of outstanding attitude and customer service, he has absolutely secured a future customer in me.

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Diligent and reliable service.

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Ronald was able to organise a brilliant electrician with extensive experience of GivEnergy systems local to me in the SW. I have now got a fully functioning system and suspect that my electricity bill will be substantially reduced or in credit over a year. Also when said electrician discovered an overvoltage in the my local grid, Ronald prepared a very lucid and comprehensive report of the situation which I have now supplied to my local grid. Cannot recommend Ron and Dan enough.

Ian Macmillan · Jul 2026 Google

My Givenergy system went offline, so I lost control of it. Ron from STS and Craig from Norfolk Solar were most helpful in diagnosing the problem by phone. Full marks for their patience and ability.

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What triggers a red fault light

Red fault lights cover a wide range of causes — from self-clearing grid events to faults needing hardware repair.

Grid overvoltage

The grid voltage at your connection point has risen above the inverter's G98/G99 limits (typically around 253V in the UK). Common in areas with high solar density. The inverter disconnects to protect the grid. Often self-clears when grid voltage drops.

Isolation fault (earth leakage)

A leakage current detected between the DC solar circuit and earth — often caused by water ingress into a junction box, MC4 connector, or cable conduit. Common after heavy rain. Self-clears when dry but the ingress point must be sealed.

Arc fault detection

The inverter's AFCI system has detected an arc in the DC wiring. Common on SolarEdge and Enphase systems. Do not reset without investigating — a confirmed arc fault represents a fire risk and requires a qualified engineer to inspect the DC cabling.

Battery communication fault

The inverter cannot communicate with the battery BMS. The inverter shows a red light while the battery side is also faulted. See battery communication fault for the full diagnostic process.

DC overcurrent or string fault

One or more solar strings is producing a current outside the inverter's expected range — from a short circuit, damaged panel, or failed optimiser. The inverter trips the affected string or all strings.

Overtemperature

The inverter has overheated — typically from poor ventilation, a blocked heat sink, or high ambient temperature combined with high output. The thermal protection trips the inverter. Usually self-clears once cooled. Check that airflow around the inverter is not blocked.

Book a diagnostic or system repair service

Arc fault codes require engineer attendance before reset. If your fault code indicates an arc fault (AFCI trip), do not attempt to reset the inverter. An arc in DC solar wiring is a fire hazard. The wiring must be inspected and the fault location identified by a qualified engineer before the system is restarted.

How to diagnose a red fault light

Start here — these steps apply to all inverter brands.

Note the light pattern and read the display

Note whether the red light is solid or flashing and at what rate. Check the inverter's own display for a fault code number. On most brands the display alternates between the fault code and other information — watch it for 30 seconds. Even "E01" or "F23" gives you something to work with.

Check the portal event log

Open your monitoring portal and look at the event log or fault history. The same fault code will be logged here, along with the exact time it triggered. Look at what happened immediately before — was there a grid event, a firmware update, heavy rain, high temperatures? Context helps identify the cause.

Look up the fault code for your brand

Use the fault code guide for your inverter brand to understand what the code means. GivEnergy, Growatt, Sunsynk, SolarEdge, and Solis all have different code numbering systems. See the brand pages and fault code guides linked below.

Attempt one controlled reset (grid and transient faults only)

For grid faults, isolation faults, and temperature trips: turn off the inverter via its AC and DC isolation switches, wait 5 minutes, turn back on (AC first, then DC). See the safe shutdown guide for the correct sequence. If the fault clears and generation resumes, monitor the portal over the next 24 hours to confirm it doesn't recur.

Do not reset if the fault code indicates: arc fault, string short circuit, hardware failure, or battery BMS fault. Do not perform more than one reset without professional input.

If the fault returns or persists — escalate

A fault that returns immediately or within a few hours of resetting indicates an ongoing problem that won't resolve itself. Continuing to reset masks the underlying cause. Book a diagnostic to get a proper assessment before the fault worsens or causes secondary damage.

Fault code guides by brand

GivEnergy fault codes GivEnergy red flashing light Growatt Sunsynk SolarEdge red light

FAQ

Frequently asked questions

What does a red light on a solar inverter mean?

A red light means the inverter has detected something outside its operating parameters and shut down as a protection measure. It is not necessarily a hardware failure — it could be a grid event, isolation fault, or overtemperature trip that will self-clear. The fault code on the display or in the portal event log tells you the specific cause.

Can I reset my inverter if it shows a red light?

A single controlled reset is reasonable for grid-related and transient faults. Turn off AC and DC isolation, wait 5 minutes, then restart. If the fault returns within a few hours, do not reset again — the underlying cause needs diagnosing. Never reset without checking the fault code first, and do not reset at all for arc fault codes.

What is the most common cause of an inverter red light?

Grid overvoltage is the most common cause — particularly in areas with high solar installation density where export from neighbouring systems pushes local grid voltage above the inverter's G98/G99 limits. Arc fault detection and isolation faults (earth leakage) are also very common.

My inverter red light appeared during rain — why?

Rain triggers isolation faults (earth leakage trips). Water ingress at a junction box, MC4 connector, or cable conduit creates leakage current between the DC circuit and earth. The inverter detects this and trips for safety. It often clears when the system dries out, but the ingress point needs to be found and sealed.

Is it safe to leave the inverter with a red light?

In most cases the inverter has shut itself down safely and is not in a dangerous state. Do not repeatedly reset. Arrange a diagnostic within a reasonable timeframe — not only because you are losing generation, but because some underlying faults can worsen if left unattended.

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