Tesla Powerwall Support — Gateway Faults, Backup & Islanding
Powerwall 2 and Powerwall 3 batteries are installed across UK homes — gateway offline, backup reserve not engaging, self-consumption modes not working, islanding failures during power cuts. We diagnose Powerwall systems remotely from app data. Remote-first. Independent from Tesla and your installer.
Gateway offline, backup not working, app not updating — we diagnose Tesla systems remotely in a single session.
Book a Remote Diagnostic — from £75 → See the Solar Health PlanSafety: do not attempt to repair the Powerwall unit itself. Gateway WiFi resets require installer credentials.
Common Powerwall 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.
Powerwall stuck at low state of charge despite solar generation. Usually caused by incorrect operating mode in Tesla app (Self-Powered vs Time-Based Control), grid connection fault, or Gateway communication issue with solar inverter. Check Energy Exports setting.
See diagnostic guide →Powerwall not feeding energy to home during peak hours or overload periods. May indicate incorrect operating mode, grid connection fault, or Gateway control issue. Check Tesla app operating mode and discharge settings.
See diagnostic guide →Operating mode (Self-Powered, Time-Based Control, Backup Reserve) not working as configured. Requires Tesla app access to review settings and energy flow logic. Gateway orchestrates the mode transitions.
See diagnostic guide →Backup circuit remains unpowered during grid outage despite battery charge. Possible causes: backup circuit not wired to Gateway, Gateway failed to island, or Powerwall in low-priority mode. Islanding is the process where Gateway detects grid down and switches.
See diagnostic guide →Backup mode triggered but backup reserve not activated. Usually caused by backup reserve set too low relative to battery SoC at time of outage. Backup reserve is the minimum charge held for emergencies. Check Tesla app backup settings.
See diagnostic guide →Gateway fails to detect grid loss and switch to island mode during outage. May be caused by slow Gateway response, islanding protection trip, or Gateway hardware fault. This is a critical safety function requiring site visit for testing.
See diagnostic guide →App shows no Powerwall data or connection lost. Gateway has lost internet connection. Check WiFi LED on Gateway (solid green = connected). If offline, check router and Gateway WiFi settings. Factory reset of WiFi may be needed after router change.
See diagnostic guide →Tesla app opens but Powerwall appears disconnected or shows stale data. May indicate Gateway connectivity issue, WiFi dropout, or cloud synchronization lag. Battery system continues operating normally even when app offline.
See diagnostic guide →Tesla Powerwall diagnostics
Tesla Powerwall doesn't display traditional fault codes — faults appear as notifications in the Tesla app and in the Gateway web interface. We diagnose issues using app notifications, Energy History data, and Gateway logs.
What we do for Powerwall owners
Remote Powerwall Diagnostic
We review Tesla app data, notification history, and Energy History to identify the exact fault without a site visit.
Tesla App & Gateway Recovery
Gateway offline, WiFi not connecting, or app access lost? We recover connectivity and reconfigure the system.
On-Site Powerwall Investigation
Island mode testing, wiring verification, backup circuit inspection, Gateway settings check. Evidence-led site visit.
Tesla Powerwall datasheets, manuals & warranty PDFs
Download datasheets, installation guides and warranty documents for Tesla Powerwall battery systems. Self-hosted and always current.
Tesla Powerwall fault code index
Having issues with your Tesla Powerwall? Our fault code index explains what each error means, common causes, and safe next steps.
About Tesla Powerwall — what you need to know
Tesla Powerwall is an AC-coupled battery storage system designed to work with existing solar installations. Powerwall 2 (13.5kWh usable) connects to the AC side of a solar inverter via the Gateway, which manages grid connection, backup switching, and energy flow. Powerwall 3 integrates a solar inverter directly into the battery unit — eliminating the need for separate solar inverter and Gateway.
The Tesla app provides monitoring and control for operating modes (Self-Powered, Time-Based Control, Backup Reserve), backup reserve levels, and scheduling. The Gateway is the brains — it detects grid loss and switches to island mode (backup) within milliseconds. Most Powerwall 2 issues come from Gateway WiFi loss, backup reserve misconfiguration, or wiring faults.
Important: Powerwall is not a solar inverter — it's a battery storage system. If you have solar on Powerwall 2, there's a separate solar inverter on your AC side. Island mode is the process where Gateway detects grid down and switches to backup — it must happen within milliseconds to avoid triggering grid protection. This is why Gateway quality and WiFi stability matter.
If you're searching for Tesla Powerwall repair UK, Powerwall not charging, Powerwall backup not working, Tesla Gateway offline, or Tesla app not updating, STS provides independent diagnostic and support across the UK — not affiliated with Tesla.
Powerwall questions answered
Powerwall charges from solar via Gateway's energy management. Common causes: incorrect operating mode in Tesla app (Settings > Customize > Energy Exports should be Self-Powered or Time-Based Control), grid connection fault, or Gateway communication issue with solar inverter. Also check that solar system is actually generating. See guide →
Backup requires Gateway to detect grid loss and switch to island mode. If didn't happen: backup reserve may be set too low (below battery SoC at time of outage), Gateway may have tripped on islanding attempt, backup circuit not wired to Gateway, or Powerwall in low-priority mode. Check Tesla app Energy History to see battery SoC at outage time. See guide →
Gateway goes offline when it loses internet connection. Check WiFi LED on Gateway — solid green = connected, off = disconnected. If offline, check your router and Gateway's WiFi settings (accessible at Gateway's IP address via browser on local network). Router change may need factory reset of Gateway WiFi settings — requires installer credentials. Battery continues operating normally even when Gateway is offline.
Powerwall units are not field-repairable — internal components are not available as spares. Tesla operates a battery swap program for in-warranty units. Out-of-warranty failed Powerwalls are typically replaced. STS can assess whether the fault is in Powerwall itself or in Gateway, solar inverter, or wiring — a remote diagnostic first is essential before concluding Powerwall needs replacement.
STS supports all major inverter and battery brands — not just Tesla Powerwall. If you have a mixed-brand system or are comparing options, visit the brand hub.
Browse all 19 brands →Ready to fix your Powerwall system?
Tell us what's happening. We'll review your details and come back with a clear diagnosis path — usually same day.