Excellent response to diagnose a problem on our SolarEdge installation. Kept us informed at every step. Diagnosis quickly completed and solution implemented.
Les Bennett · May 2026
Fault code index · SigenStor all-in-one inverter & battery
Sigenergy Fault Code Index
Every Sigenergy SigenStor alarm code — from grid protection trips and battery faults to communication errors and AFCI arc detection. Each four-digit code explained with the most likely cause and what to do next. Covers the full 1000 to 5000 series from the official alarm list.
Free remote diagnostic · pay only if we fix it — from £75 if remediable remotely
- Free remote diagnostic — results same day · no fix, no fee
- Codes visible in mySigen app & SigenCloud
- SigenStor EC 5 · 8 · 10 · 12 kW systems
SigenStor alarm you can't clear?
If your SigenStor is showing a persistent fault code in the mySigen app or has stopped exporting, a remote diagnostic identifies the cause from alarm logs and operating data — usually within 30 minutes.
Book free Sigenergy diagnosisHow diagnostics workSolar Tech Support is an absolute lifesaver. My solar and battery system stopped working completely, but after one quick phone call, they fixed the problem straight away. The original provider, GivEnergy, has gone into administration, leaving me entirely without support from the original installers. It was a terrible situation on GivEnergy’s part, but thankfully, Solar Tech Support came to the rescue!
sohaib maroof · Jul 2026 Google
Contacted Solar Tech Support in desperation. After explaining the issues I had with my system a diagnosis was made and a solution proposed. Fantastic service, even contacted a manufacturer to arrange replacement parts for me. Great communications, explained all they were doing and what I had to do, clearly and precisly. Followed up to confirm all was ok. Excellent service.
Mr Machin · May 2026
I have a GivEnergy system consisting of two batteries, two inverters and a controlling EMS (Energy Management System) which has not worked since Nov 2025. After six months I discovered Solar Tech Support, reached out to them and Ron phoned me back – how often do you get that service? Could not be more helpful – worked directly with me over the phone, outside what I would call normal working hours. Lucid explanations and we were able to discuss the issues and history using camera and email history. As this was a very rare setup, Ron was able to access an EMS expert in the field to confirm the solution. One sunny day in, I am now only paying for standing charge and a few pence for spikes in grid consumption while battery catches up with house demand.
Ian · May 2026
Contacted Solar Tech about my Givenergy battery storage system that wasn't working. Battery status was "idle". Given the company Givenergy had gone bust, I need independent quality technical help. Very patient and clearly very knowledgeable about battery systems Ron diagnosed possible issues and suggested several possible remedies. Worked our way through them and fortunately it began to work. The fault was very specific and only an experienced engineer would have thought to check. Suffice to say I'll be back if I need independent support again. Lastly you only pay if there is a solution. Outstanding.
Mr P · Jun 2026
Ron was extremely helpful and tried his best to repair/reset our GivEnergy inverter remotely. In the event he was unsuccessful but he couldn’t have been more helpful. If you have problems with a GivEnergy system please contact him. Highly recommended
Neil Crichton · Jun 2026 Google
How Sigenergy alarm codes work. Sigenergy uses a four-digit code system visible in the mySigen app and SigenCloud portal. The first digit identifies the component: 1000 = inverter, 2000 = battery, 3000 = gateway, 4000 = peripherals, 5000 = EV charger. Each code also has a sub-ID (ID1, ID2, etc.) that pinpoints the specific string, module, or circuit. Alarms appear with a timestamp and severity level in the app's event log.
Grid & AC faults
Grid protection faults are the most commonly reported Sigenergy alarms in UK installations. The SigenStor monitors voltage, frequency, and phase balance continuously and disconnects when parameters exceed G99/G98 thresholds.
1010 — Grid power outageInverter · grid powerThe inverter has detected a grid power outage or the AC isolator has been turned off. The system will reconnect automatically once the grid returns. If it does not reconnect, check whether the AC switch is on and whether the off-grid feature is enabled for off-grid-capable products. Persistent reconnection failures after a power cut may indicate a grid relay fault.
1011 — Grid overvoltage (Level I / II / III)Inverter · voltage protectionGrid voltage exceeds the overvoltage protection threshold. Level I is the lowest severity (closest to normal), Level III is the highest. Common in areas with high grid voltage — particularly during low-demand periods. The inverter disconnects until voltage returns to the safe range. If persistent, measure actual grid voltage and consult your DNO. Verify protection parameters in the mySigen app match UK grid code settings. Grid protection trip guide →
1012 — Grid undervoltage (Level I / II / III)Inverter · voltage protectionGrid voltage has dropped below the undervoltage threshold. This typically occurs during high-demand periods or on weak rural grid connections. The inverter disconnects and reconnects once voltage recovers. If it recurs frequently, check for loose connections on the AC side, verify the supply fuse rating, and contact your DNO to investigate the local grid.
1013 / 1014 — Grid frequency faultInverter · frequency protectionGrid frequency is outside the permitted range — 1013 is overfrequency (above 50.5 Hz typically), 1014 is underfrequency (below 47.5 Hz). Each has three severity levels. Frequency faults are usually grid-side events and resolve within seconds. If they persist, the grid protection parameters may be set incorrectly in the app. UK systems should comply with G99 frequency thresholds — check with your installer if in doubt.
1015 — Grid voltage imbalanceInverter · three-phaseThe voltage or phase angle across the three phases is unbalanced beyond the permitted threshold. This is a three-phase system fault. Possible causes include a dropped phase on the grid supply, unbalanced loads across phases, or a wiring fault. Measure voltage on each phase at the consumer unit and contact your DNO if the imbalance is on the supply side.
1023 / 1024 / 1025 — AC wiring faultInverter · installation1023 flags abnormal AC wiring at the inverter terminals. 1024 flags incorrect three-phase sequence — the L1/L2/L3 connections are in the wrong order. 1025 flags a short circuit between a phase conductor and PE. All three are installation wiring faults. Check the AC terminal connections at both the inverter and the consumer unit. For 1024, swap any two phases at the AC output terminal to correct the sequence.
1016 / 1017 — DC component / leak currentInverter · protection1016 means the DC component on the AC output exceeds the limit — a regulatory safety threshold. 1017 means leakage current exceeds the protection threshold. Both are transient in most cases and resolve after the environment stabilises. If either recurs, check for moisture ingress, damaged insulation on AC cables, or a faulty external RCD. Persistent 1017 faults may indicate a genuine earth leakage path that needs an electrician.
PV / Solar input faults
Solar string faults relate to the DC side — the PV panels and their connections to the inverter's MPPT inputs. Each code includes a sub-ID identifying the specific string number (ID1 = String 1, ID2 = String 2, etc.).
1002 — Low insulation resistanceInverter · DC sideThe PV string has low insulation resistance to ground — typically caused by a damaged cable, water ingress into a connector, or a panel frame earthing issue. Check DC cables for physical damage or exposed conductors. Inspect MC4 connectors for moisture. If the fault only appears in wet weather, a connector or cable joint is the likely culprit. You can also adjust the ISO protection value in the mySigen app if local regulations permit a lower threshold.
1006 — PV string input overvoltage Inverter shutdown — DC voltage exceededThe open-circuit voltage on a PV string exceeds the inverter's maximum DC input voltage. This means too many panels are connected in series on that string. The SigenStor EC range has a maximum input of 600V DC. Measure the string voltage with a multimeter — on a cold morning it will be at its highest. If it exceeds the limit, the string must be reconfigured with fewer panels in series.
1007 — PV string reverse polarityInverter · wiring errorThe positive and negative terminals of a PV string are connected the wrong way round. Wait until the string current drops below 0.5A (low light or evening), then turn off the DC switch and swap the polarity. Do not disconnect DC connectors under load — arcing can damage the connectors and is a fire risk. The sub-ID tells you which string is affected.
1008 — PV string sinking currentInverter · panel mismatchThe current on a string is inconsistent with the expected configuration — typically caused by mismatched panels, partial shading, soiling, or an occluded panel. Check whether the number of panels on the flagged string matches the design. Clean the panels if dirty. If the fault appeared after new panels were added, verify they are the same specification as the existing string. Orientation mismatches also trigger this.
1009 — AFCI fault (arc detection) DC arc detected — safety shutdownThe inverter's arc fault circuit interrupter has detected a potential DC arc on a PV string. This is a fire safety mechanism. Turn off the DC switch and inspect the string for cable damage, poor MC4 connector contact, burn marks, or loose connections at the roof junction box. After resolving the cause, clear the AFCI alarm in the mySigen app and turn the DC switch back on. Do not ignore this fault — DC arcs are a genuine fire risk.
Battery & BMS faults
Battery faults use the 2000-series codes and relate to the SigenBatt energy storage modules. These cover temperature, voltage, insulation, and internal protection events on the battery side of the system.
2002 — Battery low insulation resistanceBattery · safetyThe energy storage module has low insulation resistance to its housing. Power cycle the system — turn off DC and AC switches, wait several minutes until fully powered down, then restart. If the fault persists, the battery module may have internal condensation or a wiring fault and needs professional inspection. Battery module fault guide →
2003 — Battery over-temperatureBattery · environmentThe battery module or its power electronics have exceeded the safe operating temperature. 2003-ID1 is the power module, 2003-ID2 is the battery cells themselves. Check whether the installation location is properly ventilated, not exposed to direct sunlight, and not near a heat source. The SigenBatt has an operating range of 0°C to 50°C. Improve airflow around the unit and check for obstructed vents.
2005 — Battery under-temperatureBattery · cold weatherThe battery cell temperature is below the minimum operating threshold. Common in winter when the battery is installed in an unheated garage or outbuilding. The system will resume normal operation once the ambient temperature rises above the operating minimum. Do not attempt to force charge a cold battery — charging lithium cells below 0°C causes permanent damage. Consider relocating the battery to a warmer space if this is a regular occurrence.
2006 — Battery module overvoltage Cells overcharged — charge stoppedThe voltage of the battery module or individual cells is too high — the battery is being overcharged. The BMS shuts down charging to protect the cells. This may indicate an incorrect charge voltage setting or a cell balancing issue. Contact Sigenergy support or your installer — this fault usually requires parameter adjustment or firmware investigation. Battery module fault guide →
2007 — Battery module undervoltage Deep discharge — discharge stoppedThe battery module voltage is too low — the cells have been deeply discharged. The BMS stops discharge to prevent permanent cell damage. This can happen if the battery was left at 0% for an extended period or if the minimum SOC setting is too low. Charge the battery from AC to recover. If the battery will not accept charge, it may need professional recovery.
2008 — Battery internal protectionBattery · BMSAn internal protection event has triggered within the battery module. Sub-IDs identify the type: ID1 = input overvoltage, ID2 = output overvoltage, ID3 = overcurrent, ID4 = series voltage imbalance, ID5 = parallel current imbalance. These are often transient and resolve after the environment stabilises. If the fault recurs frequently, the battery module may have an internal issue requiring warranty investigation.
Communication faults
Communication faults affect monitoring, metering, and inter-component data exchange. The SigenStor system relies on the gateway for cloud connectivity and on CAN bus for internal component communication.
1018-ID1 — 4G communication faultInverter · connectivityThe inverter's 4G dongle has lost connectivity. Check whether the SIM card is properly inserted and has credit or data remaining. Verify 4G signal strength at the installation location. If the fault appeared suddenly, the SIM may have expired or the 4G dongle may need reseating. Top up the SIM if using a PAYG plan, or wait for 4G signal to return if the area has intermittent coverage. SigenCloud offline guide →
1018-ID2 — CAN communication faultInverter · internal busCommunication between internal components over the CAN bus has failed — typically between the inverter and the battery module. Check that all internal communication cables are firmly seated. Poor contact at floating connectors or a damaged cable causes intermittent CAN faults. Restart the equipment and wait for it to re-establish communication. If persistent, the CAN module itself may need replacement.
1018-ID3 / 4001-ID2 — Meter communication faultMetering · CT clampThe system cannot communicate with the energy meter or CT clamp. Without metering data the inverter cannot accurately manage export, self-consumption, or battery charging schedules. Check the meter communication cable is securely connected at both ends. Verify the CT clamp is properly clamped around the correct cable and oriented in the right direction. A faulty meter or loose RS485 connection is the usual cause.
1018-ID4 / 4001-ID1 — Gateway communication faultGateway · cloud connectivityThe gateway cannot communicate with the all-in-one machine. Check that the gateway communication port is reliably connected and that the air switch in the gateway is turned on. The gateway bridges the inverter/battery to SigenCloud — without it, the mySigen app shows the system as offline but the system continues to operate locally. A router restart or gateway power cycle usually resolves temporary dropouts. SigenCloud offline guide →
2004-ID4 — Battery master/slave comm faultBattery · multi-moduleIn a multi-battery configuration, the master and slave modules have lost communication. The internal link cable between battery modules may be loose or damaged. Power down the system fully, reseat the communication cables between battery modules, then restart. If one module consistently drops out, it may have an internal communication board fault.
Internal & hardware faults
Internal hardware faults indicate a problem with the inverter's or battery's physical components — power modules, control boards, fans, and internal protection circuits. Most require a power cycle as the first step.
1001 / 2001 / 3001 — Software version mismatchSystem · firmwareThe software version, hardware version, or protocol version between system components does not match. This typically occurs after a partial firmware update or when a new component is added. Retry the firmware upgrade through the mySigen app. If the upgrade fails repeatedly, contact Sigenergy support — the system may need a forced firmware push to align all components.
1003 — Inverter over-temperatureInverter · thermalThe inverter's internal temperature has exceeded its safe limit. Caused by high ambient temperature, poor ventilation at the installation location, direct sunlight exposure, or an internal power module generating excess heat. Check that the unit has adequate clearance for airflow and is not in direct sun. If the fault persists in normal conditions, the internal cooling system may need inspection.
1004 — Equipment fault (hardware) Internal circuit fault — power cycle requiredAn internal hardware component has failed. Sub-IDs identify the module: ID1 = power module, ID2 = control module, ID3 = auxiliary power supply, ID4 = PID module, ID5 = monitoring module, ID6 = heating film, ID7 = external fan. Power cycle the system — turn off DC and AC, wait several minutes, then restart. If the fault returns, the specific module identified by the sub-ID likely needs replacement under warranty.
1005 — System grounding faultInverter · earthingThe protective earth (PE) cable is not properly connected. Verify the PE wire is securely connected at the inverter's grounding terminal and at the earth bar in the consumer unit. A loose or corroded earth connection triggers this fault. If the wiring is correct and the fault persists, the inverter's internal ground detection circuit may need investigation.
1019 — Internal protection (MPPT / BUS)Inverter · transientAn internal overcurrent or overvoltage protection event has triggered. ID1–16 cover MPPT overcurrent on individual strings, ID17 = inverter output overcurrent, ID18 = BUS overvoltage, ID19 = BUS voltage imbalance, ID20 = internal control protection. Often transient — caused by environmental changes like sudden cloud cover or temperature swings. The system usually resumes automatically. If it recurs over an extended period, report via the mySigen app.
1026 — Soft start failureInverter · startupThe inverter failed to complete its soft start sequence when powering on. This is often transient and caused by unstable grid conditions during startup. Wait a few minutes and the system will retry automatically. If the fault persists after multiple retries, power cycle the system fully. Repeated soft start failures may indicate a relay or pre-charge circuit fault inside the inverter.
Off-grid & backup faults
Off-grid faults trigger when the SigenStor is operating in backup (EPS) mode during a power cut or in an off-grid installation. The 3000-series gateway codes also appear here for system-level wiring faults.
1021-ID1 — Off-grid overloadBackup · EPSThe load on the off-grid / backup circuit exceeds the inverter's rated output power. During a power cut, high-draw appliances like kettles, ovens, and immersion heaters can exceed the SigenStor's backup capacity. Reduce the load by switching off non-essential appliances on the backed-up circuit. If the system is permanently off-grid, the total connected load needs to stay within the inverter's continuous rating.
1021-ID2 — Off-grid short circuit Immediate shutdown — check wiringA short circuit has been detected on the off-grid output. The inverter shuts down immediately to protect itself and the connected loads. Check all wiring on the backed-up circuit, including appliances, extension leads, and the consumer unit connections. Identify and isolate the faulty circuit before restarting. Do not repeatedly restart the inverter into a short circuit.
1021-ID3 — Off-grid output overvoltageBackup · voltageThe voltage on the off-grid output exceeds the safe threshold. This is typically transient and caused by sudden load changes — a large load switching off creates a momentary voltage spike. If it recurs frequently, the off-grid output circuit may have a wiring issue or the inverter's voltage regulation may need inspection.
1022 — EPO protection (emergency stop)Safety · manualThe rapid shutdown / emergency power off (EPO) button has been pressed. The system will not restart until the EPO is released. Confirm there are no safety hazards at the scene, then release the EPO button. If no physical EPO button exists, the EPO may have been triggered via the mySigen app — check the app for a manual shutdown command.
3008 — Grid phase lossGateway · three-phaseOne or more phases of the three-phase grid supply are missing. The grid voltage is not fully connected to the equipment. Check the terminal wiring on the grid side to ensure all three phases are connected. A blown fuse on one phase at the consumer unit or a supply fault from the DNO can cause this. Single-phase systems will not see this alarm.
Fault code not listed here?
The Sigenergy alarm list contains over 100 individual codes across the 1000–5000 series. This page covers the faults most commonly seen in UK residential installations. If you have a code that isn't listed, share the four-digit alarm code and sub-ID from the mySigen app and we'll identify it.
Full diagnostic guides by fault type
1011 · 1012 · 1013 · 1014 · G99
Grid protection trip
Full diagnostic — voltage and frequency trips, UK grid code settings, and when to contact your DNO.
2002 · 2006 · 2007 · 2008 · BMS
Battery module fault
Battery over/undervoltage, insulation resistance, internal protection events, and SigenBatt warranty process.
1018 · 4001 · 4G · gateway · Wi-Fi
SigenCloud offline
Gateway connectivity, 4G dongle, meter communication, and getting SigenCloud back online.
Sigenergy fault code questions
Sigenergy fault codes appear in the mySigen app on your phone or tablet. Open the app, select your system, and navigate to the alarm or event log. Each alarm shows a four-digit code (such as 1011 or 2006), a description, and a timestamp. The same alarms are visible in the SigenCloud web portal if your system has gateway connectivity. The first digit tells you the component: 1000 = inverter, 2000 = battery, 3000 = gateway, 5000 = EV charger.
Sigenergy uses a four-digit alarm code system. The first digit identifies the component: 1000-series = inverter, 2000-series = battery, 3000-series = gateway, 4000-series = peripherals, 5000-series = EV charger. Within each code, a sub-ID (ID1, ID2, etc.) identifies the specific fault — for example, 1006-ID1 means String 1 input overvoltage. This structure helps narrow down whether the problem is solar, battery, grid, or communication.
Repeated grid overvoltage (1011) or undervoltage (1012) alarms are common where the local grid voltage is unstable or near the permitted limits. The SigenStor's grid protection must comply with G99/G98 requirements, and these thresholds are tighter than some inverter brands. If the grid voltage genuinely exceeds the threshold, the inverter disconnects — this is correct behaviour. If it happens frequently, ask your DNO to check local grid voltage and verify the protection parameters in the mySigen app match the correct UK grid code. Grid protection trip guide →
STS offers remote diagnostic assessments from free. Sigenergy systems log detailed alarm history, power data, and operating parameters in the mySigen app and SigenCloud portal. Our engineers can analyse this data remotely to identify the root cause and recommend the fix — whether that is a settings change, a firmware update, or a site visit for hardware inspection.
Many faults clear automatically once the triggering condition resolves — for example, a grid voltage fault clears when the grid returns to normal. For persistent faults, power cycle the system by turning off the AC and DC isolators, waiting two minutes, then switching back on: DC first, then AC. Some faults like AFCI alarms (1009) must be manually cleared in the mySigen app after checking the DC cables. If a fault returns after reset, the underlying cause needs investigation — repeated cycling without diagnosis can mask a genuine problem.
Book
SigenStor alarm you can't resolve?
Share the alarm code from the mySigen app, when it first appeared, and whether the system is still generating. We'll analyse the alarm history and operating data remotely and tell you whether it needs a settings change, firmware update, or site visit.
- Not affiliated with Sigenergy
- No fix, no fee
- Written report with cause and recommended action
We use cookies to measure traffic and improve our ads — including sharing limited, hashed details with Meta (Facebook) to measure ad performance. Accept, or decline for essential cookies only. Privacy policy
STS Solar Tech Support
Usually replies within minutes
Hi there!
Got a solar fault or need a quick answer? Drop us a message — we usually reply within a few minutes. Mon–Fri, 9am–7pm.
Start WhatsApp Chat
Got a solar fault or need a quick answer? Drop us a message — we usually reply within a few minutes. Mon–Fri, 9am–7pm.
End-to-end encrypted