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Brand support · Huawei

Huawei SUN2000 Support — AFCI Faults, Battery Charging & FusionSolar

Fast-growing hybrid inverter brand with modular LUNA2000 battery. AFCI trips, BMS communication errors, FusionSolar portal offline, SPS mode faults — we diagnose Huawei systems at the engineering level. Remote-first, but WiFi isn't remote work: if the dongle needs reconnecting to your WiFi, we can set it up on site, from £195. Independent from Huawei and your installer.
Free remote diagnostic £125 only if we fix it remotely
  • Not affiliated with Huawei
  • All SUN2000 models — G3, G4, G5
  • LUNA2000 battery diagnostics
Not sure where to start?

AFCI trip or battery not charging — we diagnose SUN2000 systems remotely in a single session. FusionSolar offline? Follow our FusionSolar offline guide, and if the dongle needs reconnecting to your WiFi, we can set it up on site, from £195.

Book your free remote diagnosticFusionSolar offline guide

Safety: do not open inverter or battery enclosures. If you smell burning or see arcing, isolate at the consumer unit and call 999.

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.

Philip Davey · Jun 2026 Google

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

Great service in supplying and fitting an additional GivEnergy battery. Went the extra mile in managing to fit the battery in to a difficult space.

Jules TIlley · Sep 2026 Google

Thank you for your diligence. On this occasion the battery was able to be saved but they have given a route to hopefully arrange a repair from the manufacturer.

David Bateman · Jun 2026 Google

I can’t praise this firm enough. After hearing my solar panels rattling in very windy conditions, I contacted Solar Tech (as my installers no longer trade). Ronald was fantastic at explaining what he thought the issue was likely to be. Communication was great throughout keeping me fully updated. The team worked really hard on the day to carry out the necessary work. I can now sleep soundly at night without worrying about the solar panels on my roof. I would thoroughly recommend this firm. Thank you for sorting the problem out.

Carolyn Addison · Jun 2026 Google

I work for a Solar Company and had a customer with a GivEnergy system that we are not versed in. Ron took the time to explain the issues my customer was having and between us managed to rectify the issues. 10 Stars ... Thanks again STS

Craig Daly · Jun 2026 Google
Huawei Faults

Common Huawei problems we diagnose

Every fault below has a proven diagnostic path. Click through for the specific page or book a diagnostic if you're unsure.

Fault Codes

Huawei fault code index

Seeing an error code in FusionSolar or on the inverter? Our full Huawei fault code index explains what each code means, common causes, and safe next steps.

Fault code categories

  • · AFCI arc fault codes — DC cable protection
  • · BMS communication alarms — battery faults
  • · Grid protection faults — G98/G99 events
  • · SPS storage protection — backup mode faults
  • View all Huawei fault codes
Services

What we do for Huawei owners

All services

Remote Huawei Diagnostic

We review FusionSolar data, app settings, and error history to identify the exact fault without a site visit.

  • Fault path identified
  • Settings validation
  • Written engineer summary
Book remote diagnostic

Huawei System Recovery

Installer gone bust, FusionSolar access lost, account locked. We recover portal access and rebuild documentation.

  • Portal ownership transfer
  • API access recovery
  • Warranty evidence pack
Start recovery

On-Site Huawei Repair

CAN cable rewire, BMS communication fix, SPS circuit verification, firmware update, hardware swap. Targeted visit — no guesswork on arrival.

  • Evidence-led targeted checks
  • Safety-focused report
  • Repair or replacement path
Discuss visit
Documents

Huawei datasheets, manuals & warranty PDFs

Download datasheets, installation manuals and warranty documents for Huawei SUN2000 inverters and LUNA2000 batteries. Self-hosted and always current.

  • Product datasheets & specifications
  • Installation & commissioning manuals
  • Warranty terms & coverage documents
  • App & software setup guides
  • Wiring diagrams

About Huawei systems — what you need to know

Huawei is one of the UK's fastest-growing solar battery brands, known for their hybrid inverters, all-in-one units, and modular battery stacks. The SUN2000 inverter series (G3, G4, G5 generations) pairs with the LUNA2000 battery for scalable storage. Their systems communicate over a CAN bus between the inverter and battery — a common fault path when communication breaks down after firmware updates or power interruptions.

The FusionSolar app and portal provide monitoring and configuration. When the Smart Logger or WiFi dongle loses connection — due to router changes, firmware bugs, or hardware failure — the portal goes dark, though the system usually keeps running, so check the inverter's own screen or status lights. The SPS (Sustainable Power Supply) backup mode requires both dedicated wiring and correct FusionSolar settings to engage during grid outages.

Huawei systems work with grid codes G98 (up to 16 A per phase) and G99 (anything bigger) in the UK. Incorrect configuration can cause repeated disconnections. Many reported issues with battery not charging trace back to incorrect charge window settings, BMS communication faults, or grid code misconfigurations. If you're searching for Huawei repair UK, Huawei battery not charging, Huawei AFCI fault, Huawei FusionSolar offline, or Huawei BMS communication fault, STS provides independent diagnostic and repair support across the UK — not affiliated with Huawei.

We also support

STS supports all major inverter and battery brands — not just Huawei. If you have a mixed-brand system or are comparing options, visit the brand hub.

FAQ

Huawei questions answered

The AFCI (Arc Fault Circuit Interrupter) detects abnormal arc conditions on DC cabling. A single AFCI trip may be a nuisance event — power cycling will clear it if the arc is not persistent. If the fault returns, inspect MC4 connectors and DC cable insulation for damage. Repeated AFCI trips indicate a real fault. See the Huawei AFCI guide →
LUNA2000 batteries fail to charge for several common reasons: incorrect working mode in FusionSolar settings, a BMS communication alarm between battery and inverter, low SoC protection, or grid code faults preventing export. Check the FusionSolar app alarm log for the specific code. See the Huawei battery charging guide →
The FusionSolar app goes offline when the Huawei Smart Logger or WiFi dongle loses its internet connection. Check the link LED on the dongle — solid means connected, flashing means trying to connect. A power cycle of the inverter (AC then DC off, wait 60 seconds, back on) often restores the connection, and if it still won't connect, we can set it up on site, from £195. See the FusionSolar offline guide →
Yes. BMS comms faults between LUNA2000 battery modules and the SUN2000 inverter are usually caused by firmware mismatch, loose CAN cable, or a battery module in protection state. Many can be recovered remotely. We diagnose using FusionSolar alarm data and on-site CAN bus checks where needed. See the Huawei battery diagnostic guide →
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Ready to fix your Huawei system?

Tell us what's happening. We'll review your details and come back with a clear diagnosis path — usually same day.

  • Not affiliated with Huawei
  • No fix, no fee covers remote fixes. On-site work is quoted in writing before we start.
  • On-site visits available

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Call 07944 877 329 Book free diagnostic