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Fault code index · Huawei SUN2000 inverter & LUNA2000 battery

Huawei SUN2000 Fault Code Index

Every Huawei SUN2000 fault code from FusionSolar — what it means, the most likely cause, and what to do. Find your code in the index below or use the category sections to browse by system area.

Huawei SUN2000 all models and generations LUNA2000 battery fault codes included Sourced from Huawei technical documentation

Huawei SUN2000 Fault Code Index

Every Huawei SUN2000 fault code from FusionSolar — what it means, the most likely cause, and what to do. Find your code in the index below or use the category sections to browse by system area.
  • Huawei SUN2000 all models and generations
  • LUNA2000 battery fault codes included
  • Sourced from Huawei technical documentation
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13 Trustpilot reviews
Trustpilot Google

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 Trustpilot

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.

Sree · May 2026 Trustpilot

Ron want out of is way to help, nothing was to much. He was very thorough in what he did Very knowledgeable I would highly recommend Ron and his company He did a fantastic job for me. if you have any problems, he'll do his best to help you out and resolve your problem. I wouldn't hesitate to recommend them

Dennis Brown · May 2026 Trustpilot

Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)

Tony Deacon · May 2026 Trustpilot

Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone

Phill · May 2026 Trustpilot

I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues

michael fairhurst · May 2026 Trustpilot

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 Trustpilot

After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.

Keith Ballard · Apr 2026 Trustpilot

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026 Trustpilot

Ron is a super star. Two months ago my GivEnergy battery failed a firmware upgrade leaving it a brick. My installer couldn't/wouldn't fix it. GivEnergy couldn't/wouldn't fix it. Then they went into administration and all hope was lost. A flurry of emails later and Ron had diagnosed the fault (failed USB flash drive, something I'd suspected) and talked me through resolving it. Two months of nothing resolved in about 3 hours. It's great to work with someone who pays attention to the details, knows that they're doing (not just following a script) and gets stuff sorted without a fuss or up-charging.

Christopher · Apr 2026 Trustpilot

I can add to the list of customers who had already 'given up' on GivEnergy due to their appalling customer service, and that was before they went into administration (their Trustpilot reviews don't lie!). So you can imagine my desperation when, having changed my ISP and my Inverter, predictably, proving to be the only device that didn't connect automatically to my new network, I found zero prospect of any customer support with GivEnergy having called in the administrators just five days earlier! The salvation came from Solar Tech Support. My IT advisor stumbled across their web site and some very helpful tips for beleaguered GivEnergy customers, as well as an offer to provide direct assistance. Nothing ventured, I decided to drop them an E-Mail, with very low expectations based on my experience of GivEnergy customer support. Within an hour Ron had responded with some pin point advice, and after a few exchanges of E-Mails he had nailed the problem, enabling the combined efforts of my IT advisor and solar installer to resolve it and reconnect my Inverter. Thank you Solar Tech Support, and Ron in particular, for coming to the aid of a deserted and despondent GivEnergy customer. Expert, razor sharp advice and first class customer service, even though I wasn't officially a customer.

customer · Apr 2026 Trustpilot

This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.

Andy Thomas · Apr 2026 Trustpilot

I sent a message on their website regarding a problem I have on my Givenergy system. Although not supplied by Ronald, I thought it was worth an email. Within the hour on a Saturday, he phoned and we discussed the problem. He logged in remotely and gave excellent advice. I'm too far away for his on-site help but he did diagnose the problem and was happy also to chat through my thoughts about an upcoming solar/battery install I'm planning. Great bloke.... if only he was nearer!

Philip · Apr 2026 Trustpilot

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 Trustpilot

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.

Sree · May 2026 Trustpilot

Ron want out of is way to help, nothing was to much. He was very thorough in what he did Very knowledgeable I would highly recommend Ron and his company He did a fantastic job for me. if you have any problems, he'll do his best to help you out and resolve your problem. I wouldn't hesitate to recommend them

Dennis Brown · May 2026 Trustpilot

Ron took me through a diagnostic to confirm my GivEnergy Inverter had a fault. A common one as it turns out with the AC Inverter. As GivEnergy is defunct there is no immediate fix, aside from sourcing 2nd hand replacement. It may be that a fix becomes available over the summer which would make a lot of GivEnergy customers happy (Again)

Tony Deacon · May 2026 Trustpilot

Contacted Ron with a problem and he sorted it out quickly with no problems at all. Very knowledgeable on anything solar/ batteries. I would recommend him to anyone

Phill · May 2026 Trustpilot

I've spoken to Ron a couple of times with issues with my Givenergy installation. Such a friendly knowledge guy very highly recommended. Thank you very much for resolving my issues

michael fairhurst · May 2026 Trustpilot

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 Trustpilot

After GivEnergy went into liquidation, just my luck, my battery started playing up (internal board crashed). Contacted my installer - not interested! Found Solar tech support on a Google search. Sooo glad I found this company! Ron is extremely helpful and has plenty of experience. He soon confirmed what the fault was, and helped me to get my system up and running again. Now moved my GivEnergy account to Solar tech support, and will definitely use again if I have more issues. Unusual to find such a helpful company in these times, no morons reading scripts, just direct contact with the engineer.

Keith Ballard · Apr 2026 Trustpilot

Contacted Solar Tech Support when trying to understand what my Givenergy inverter problem might be and what might be my options. Received good/honest advise which backed up my thoughts.

Hugh Speirs · Apr 2026 Trustpilot

Ron is a super star. Two months ago my GivEnergy battery failed a firmware upgrade leaving it a brick. My installer couldn't/wouldn't fix it. GivEnergy couldn't/wouldn't fix it. Then they went into administration and all hope was lost. A flurry of emails later and Ron had diagnosed the fault (failed USB flash drive, something I'd suspected) and talked me through resolving it. Two months of nothing resolved in about 3 hours. It's great to work with someone who pays attention to the details, knows that they're doing (not just following a script) and gets stuff sorted without a fuss or up-charging.

Christopher · Apr 2026 Trustpilot

I can add to the list of customers who had already 'given up' on GivEnergy due to their appalling customer service, and that was before they went into administration (their Trustpilot reviews don't lie!). So you can imagine my desperation when, having changed my ISP and my Inverter, predictably, proving to be the only device that didn't connect automatically to my new network, I found zero prospect of any customer support with GivEnergy having called in the administrators just five days earlier! The salvation came from Solar Tech Support. My IT advisor stumbled across their web site and some very helpful tips for beleaguered GivEnergy customers, as well as an offer to provide direct assistance. Nothing ventured, I decided to drop them an E-Mail, with very low expectations based on my experience of GivEnergy customer support. Within an hour Ron had responded with some pin point advice, and after a few exchanges of E-Mails he had nailed the problem, enabling the combined efforts of my IT advisor and solar installer to resolve it and reconnect my Inverter. Thank you Solar Tech Support, and Ron in particular, for coming to the aid of a deserted and despondent GivEnergy customer. Expert, razor sharp advice and first class customer service, even though I wasn't officially a customer.

customer · Apr 2026 Trustpilot

This company are a rare gem, I had a very unusual problem following a failed firmware upgrade on my GivEnergy kit. I then found out GivEnergy were in administration and had dismissed all their support staff! None of the usual fixes to try and restore my inverter comms would work, and I looked everywhere, forums, GivEnergy youtube support videos - even AI couldn't figure it out. My installer was talking about huge sums for system replacements, and being vague / evasive about if they'd even install replacement GivEnergy inverter. Enter Solar Tech Support, reassuring and knowledgeable from the very start, I've learnt loads about my solar system though the friendly chat while my engineer worked as he diagnosed the problem and figured out a fix procedure that I've not found anywhere else - amazing . If you need solar system repairs - especially if you like me have been left high and dry by GivEnergy, I cannot recommend this company enough. Give them a call.

Andy Thomas · Apr 2026 Trustpilot

I sent a message on their website regarding a problem I have on my Givenergy system. Although not supplied by Ronald, I thought it was worth an email. Within the hour on a Saturday, he phoned and we discussed the problem. He logged in remotely and gave excellent advice. I'm too far away for his on-site help but he did diagnose the problem and was happy also to chat through my thoughts about an upcoming solar/battery install I'm planning. Great bloke.... if only he was nearer!

Philip · Apr 2026 Trustpilot
How to find your fault code. Huawei fault codes appear in the FusionSolar mobile app and web portal. Log into FusionSolar → Device → Alarm History. The alarm history shows fault codes (e.g., Fault 2001, Fault 3004) with timestamps. Note the exact fault number — this will help you find the correct entry in this index to understand what it means and how to resolve it.
Grid faults

Fault codes generated in response to AC grid voltage or frequency being outside safe operating limits. These cause the inverter to disconnect from the grid.

Fault 2001 Grid overvoltage
AC grid voltage has exceeded the upper safety limit (typically above 253V). Inverter has disconnected to protect itself and the grid. This is usually a temporary grid disturbance. Monitor the alarm history — if frequent, contact your DNO.
Fault 2002 Grid undervoltage
AC grid voltage has dropped below the lower safety limit (typically below 216V). Inverter has disconnected. This often occurs during high-load periods. Wait for grid voltage to recover — the inverter will reconnect automatically.
Fault 2003 Grid overfrequency
Grid frequency has exceeded the upper safety limit. Inverter disconnected. Frequency events usually affect many users in your area. The inverter will reconnect when frequency normalizes.
Fault 2004 Grid underfrequency
Grid frequency has dropped below the lower safety limit. Inverter disconnected. This indicates a significant grid disturbance — wait for frequency to recover and the inverter will reconnect automatically.
Fault 2006 Grid frequency instability
Grid quality is poor — frequency is fluctuating rapidly. Inverter may disconnect and reconnect frequently. This is a grid quality issue affecting your area. Contact your DNO if the problem persists.
PV & DC faults

Fault codes related to DC string voltage, polarity, and insulation. These faults typically prevent the inverter from generating power.

Fault 3001 PV overvoltage
PV string voltage is exceeding the MPPT input range. Check panel string configuration — may have too many panels in series. Do not touch DC cabling. Contact an engineer to review the string design.
Fault 3002 ⚠ PV reverse connection
One or more PV strings have been connected with reversed polarity (positive and negative swapped). This is a critical safety issue. Isolate the system immediately. Do not touch any DC cabling. Contact a qualified engineer to identify which strings are reversed and reconnect them correctly.
Fault 3003 ⚠ DC arc fault — URGENT
A DC arc has been detected in the PV string — this is a fire safety hazard. Isolate the system at the consumer unit immediately. Do not touch any DC cabling. Contact a qualified engineer to inspect string cabling and connectors for damage or loose connections.
Fault 3004 ⚠ Insulation resistance fault — URGENT
Leakage current has been detected between the DC string and earth — a ground fault. This is a critical safety issue. Isolate at the consumer unit immediately. Do not touch any DC cabling. Check for water ingress at MC4 connectors, damaged insulation, or a faulty panel junction box. Contact a qualified engineer.
Battery & BMS faults

Fault codes from the LUNA2000 battery management system — communication failures, voltage protection, temperature, and state of charge events.

Fault 4001 Battery comm fault
Communication lost between inverter and battery BMS. Check the SBU/BMU communication cable is connected securely at both ends. Verify polarity is correct. Try a full power cycle of the system.
Fault 4002 Battery overcurrent
Discharge current from the battery has exceeded safe limits. BMS has activated protection. Check that no unusual loads are connected to the backup circuits. If using backup power, reduce load and try again. Contact Huawei support if persistent.
Fault 4003 Battery overtemperature
Battery internal temperature has exceeded safe limits. Check that ventilation around the battery cabinet is clear and unobstructed. Ensure no heat sources are nearby. If ambient temperature is normal, the battery may have a thermal sensor issue — contact Huawei support.
Fault 4004 Battery SOC too low
Battery state of charge has fallen below the safe minimum threshold. BMS has activated deep discharge protection. Allow the battery to charge fully during daylight. If persistent, check discharge cut-off SOC settings in battery options.
Fault 4005 BMS protection active
Battery management system has activated a protection event. This typically means a specific cell voltage or temperature limit has been reached. Check FusionSolar for more details — a full power cycle may be needed.
Internal & thermal faults

Fault codes originating from inside the inverter — processor communication, temperature management, and control board issues.

Fault 1001 DSP comm fault
Internal processor communication fault. Perform a full power cycle (AC isolator off, wait 60 seconds, back on). If the fault persists, the control board may require a firmware reflash — contact Huawei support or a qualified engineer.
Fault 1002 Inverter overtemperature
Internal heatsink temperature has exceeded safe limits. Check ventilation — ensure minimum 20cm clearance on all sides, no direct sunlight, and no enclosed cabinets. Clear any dust from cooling vents. If ambient temperature is normal, the thermal sensor may be faulty.
Frequently asked questions
How do I access FusionSolar to see my alarm history?
Download the FusionSolar mobile app or visit the web portal at https://global.fusionsolar.huawei.com. Log in with your account credentials. Select your device, then go to Alarm History or Device Events to view all fault codes with timestamps and descriptions.
Why does Fault 2001 (grid overvoltage) appear during sunny afternoons?
During peak solar generation in the afternoon, many solar systems in your area are exporting power to the grid simultaneously. This can cause grid voltage to spike. If Fault 2001 appears frequently during peak hours, it indicates a grid quality issue. Contact your DNO to investigate.
What's the difference between temporary faults and persistent faults?
Transient faults appear once or occasionally — usually grid disturbances or brief communication glitches. These often clear automatically. Persistent faults return repeatedly after power cycles and require diagnosis. Check your alarm history to see if the fault is trending or one-off.
Should I be worried if I see battery faults in the alarm history?
Many battery faults are protective events that trigger when limits are approached — not catastrophic failures. Fault 4004 (SOC low) is common if your battery has fully discharged. Fault 4003 (overtemperature) can occur in hot weather. If the same fault repeats after proper charging/cooling, then diagnosis is needed.

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