Prompt and useful support regarding my Sunsynk system lack of performance. Ronald simplified the technical issues to make them understandable. Many thanks, looking forward to follow up.
Patrick Keenan · May 2026 Trustpilot
Diagnostic guide · Tesla Powerwall
Tesla Gateway or app offline?
Your Powerwall still works without internet, but you have lost app monitoring and remote control. The issue is usually WiFi band mismatch, router firewall port 1883 blocked, or Gateway lost network credentials. Follow these 6 diagnostic steps for Gateway 2 and Gateway 3.
from £195 on-site WiFi setup · extender £75 extra if needed
- Powerwall 2 and Powerwall 3
- The step-by-step guide is free to follow
- Not affiliated with Tesla
Gateway offline, but Powerwall works?
If you've tried the steps below and the Gateway still won't connect, we can set it up on site, from £195. Tell us your Gateway model, WiFi band (2.4GHz or 5GHz), whether you changed routers recently, and what LED colour you see.
Book on-site WiFi setupTesla Powerwall hubIndependent — not affiliated with Tesla Inc.
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 Trustpilot
Great advice from Ronald at Solar Tech Support, got my inverter back on line and stable.
Mervyn Ethelston · Aug 2026 Google
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 Google
Genius when it comes to solar and off grid installations we spent days trying to work out what was causing our problems and Ron resolved it in less than an hour! Cant reccomend enough
Ben Carroll · Aug 2026 Trustpilot
Wow... a firmware update to my inverter sent the whole system into meltdown – the battery discharged, and the house seemed to be drawing power, and the solar, who knows where that was going? Aghhh... A short email exchange with Roland and Solar Tech Support sorted the problem... the firmware had reversed a setting (from when it was installed), and the CT clamp needed to be reversed. As soon as I had done that, the world returned to normal. Thanks, Roland; there is no way I would have come to that conclusion. Would I recommend them? You bet! Worth the fee? You bet, again!
Pete Hawkins · Jul 2026 Google
Before you start: the Powerwall usually keeps running, but the app can't show you a fault until the Gateway reconnects. You lose Tesla app monitoring, remote control, and server-side features like Storm Watch, but your backup power, solar charging, and self-consumption settings stay as configured. The issue is most likely just the communication bridge between your home and Tesla servers.
Diagnosis
Step-by-step Gateway offline diagnosis
Work through these steps in order. Step 1 checks the physical LED. Step 2 covers WiFi band compatibility — the most common cause. Steps 3–6 cover reconnection methods, Ethernet, firewall port rules, and power cycling.
1
Check the Gateway LED status
Look at the LED indicator on your physical Gateway unit. Solid green = connected and communicating with Powerwall. Flashing green = enabled but no communication with Powerwall — local connection issue. No light = no power to the Gateway — check your circuit breaker or wall outlet. On Gateway 3: green plus light blue = ready for initial commissioning. Flashing red = firmware update in progress — do not power off, wait for completion.
2
Check your WiFi network frequency band
This is the #1 cause of Gateway offline issues. Gateway 2 supports 2.4GHz ONLY — not 5GHz. If your router defaults to 5GHz-only or has merged 2.4/5GHz bands, the Gateway cannot connect. Gateway 3 supports both 2.4GHz and 5GHz. If you recently changed routers, your new router may have different default band settings. Check your router admin panel and ensure 2.4GHz is available and your Gateway is connecting to it. Also verify signal strength — minimum 2-3 bars required. If the Gateway is too far from the router, move it closer or add a WiFi repeater. If the signal still won't reach, we can fit a WiFi extender on site: our WiFi setup visit is from £195, and the extender is an extra £75.
3
Reconnect WiFi via the Tesla app
Open the Tesla app and tap on your Powerwall. Go to Settings > WiFi. Select your home network and enter the password. Wait 2-3 minutes for the Gateway to reconnect to Tesla servers. If the Tesla app cannot reach your Gateway remotely, you can connect directly to the Gateway's local WiFi network: look for a network named TEG-xxx (where xxx is the last three characters of your unit's serial number). Connect your phone to this network with the password on the Gateway's QR label: on Gateway 2 the label is behind the glass door, and you can scan its QR code instead of typing the password. Then open the Tesla app again — it will now see the local Gateway — and configure your home WiFi from there.
4
Check Ethernet connection if available
Tesla recommends configuring BOTH Ethernet and WiFi for maximum reliability. The Gateway will auto-select whichever connection is available and fastest. Use minimum CAT5 cable (CAT6 or CAT7 preferred). Verify the cable is fully seated in both the Gateway jack and your router port — push until you hear a click. If Ethernet still is not working, try connecting to a different port on your router — one port may be faulty. Inspect the cable for any visible damage or bent pins.
5
Check router firewall and port 1883
The Gateway uses the MQTT protocol on port 1883 to communicate with Tesla servers. Some routers block this port by default or after firmware updates. Log into your router admin panel and look for firewall rules or port blocking settings. Port 1883 must be open for outbound traffic. Also check if MAC address filtering is enabled — if it is, whitelist the Gateway's MAC address (usually printed on the unit or visible in the Tesla app). After any router firmware update or router change, power cycle both your router and the Gateway — turn them off for 30 seconds, then turn them back on.
6
Power cycle the Gateway
Turn off the Gateway circuit breaker, wait 30 seconds, turn it back on. Allow 5 minutes for the system to fully reconnect and sync with Tesla servers. The LED should change from offline (no light or flashing) to solid green when successfully connected. Do not open the Gateway to press its reset button: Tesla states the Gateway is not user-serviceable. If it is still offline after 5 minutes and it's the WiFi or the router, we can set it up on site, from £195: book on-site WiFi setup.
Gateway offline vs Powerwall offline — why it matters
When your Gateway goes offline, the communication bridge between your home and Tesla servers is broken. On its own, the Powerwall usually keeps running, but the app can't show you a fault until the Gateway reconnects. The battery system is designed to work in autonomous islanding mode — it detects local solar generation, powers your home, manages backup energy, and provides backup power during power cuts without needing internet or app instructions. All of this happens locally. The Gateway is just the remote monitoring layer. This is why the app showing offline doesn't by itself stop your backup power: the Powerwall never relied on cloud servers for its core functions.
The Gateway's job is to relay your system status to the Tesla app, allow you to change settings remotely, enable Storm Watch (UK Met Office weather integration), and push firmware updates. If the Gateway is offline, you cannot change settings from the app, you cannot see live power flows or battery SOC, and Storm Watch cannot auto-charge your battery before bad weather. But the Powerwall keeps the settings you last gave it: backup reserve stays set and self-consumption mode stays active. If the Gateway needs reconnecting to your WiFi, we can set it up on site, from £195: we connect it to your WiFi, set up your router, including a separate 2.4 GHz network if it needs one, and check it's reporting. STS is independent of Tesla and your installer.
Related Tesla guides
Cross-brand & guides
Gateway offline — common questions
Your Gateway has lost internet connection. Common causes: WiFi disconnected after you changed routers, port 1883 blocked by your router's firewall, your new router defaults to 5GHz but your Gateway is Gateway 2 (2.4GHz only), or a temporary Tesla server outage. Meanwhile, the Powerwall usually keeps running, but the app can't show you a fault until the Gateway reconnects. You lose app monitoring and remote control, but your backup, solar charging, and self-consumption settings stay as configured on your local system.
The LED indicator tells you the Gateway's connection status. Solid green = connected and communicating with Powerwall and Tesla servers. Flashing green = enabled but not communicating with Powerwall — local connection issue. No LED = no power to the Gateway — check your circuit breaker. Flashing red = firmware updating — do not power off, wait for completion. Green plus light blue (Gateway 3 only) = ready for initial commissioning. If you see no LED but the Gateway has power, the LED itself may be faulty.
Standard method (if the Tesla app can reach your Gateway): Tesla app > Powerwall > Settings > WiFi > select your home network and enter the password > wait 2-3 minutes. If the app cannot reach your Gateway: connect your phone to the Gateway's local WiFi network (look for TEG-xxx, where xxx is the last three characters of your serial number) > open the Tesla app — it will now find the local Gateway > configure your home WiFi from the app. After you change routers, always power cycle both your router and the Gateway for at least 30 seconds to clear old network associations. If it still won't connect, we set it up on site, from £195: we connect it to your WiFi, set up your router, including a separate 2.4 GHz network if it needs one, and check it's reporting.
Yes. The Powerwall doesn't need the internet for backup power, solar charging or self-consumption, and your backup reserve and mode settings stay active. The internet is only needed for the Tesla app's monitoring and remote control, firmware updates, Storm Watch and Tesla's server-side analytics. If your Gateway is offline, the Powerwall usually keeps running, but the app can't show you a fault until the Gateway reconnects.
Three things usually happen when you change routers. First, WiFi credentials change — your old router's SSID and password no longer work, but the Gateway still has the old credentials stored in memory. Second, frequency band issue (Gateway 2 only) — if your new router defaults to 5GHz-only or merged 2.4/5GHz bands, Gateway 2 cannot connect because it only supports 2.4GHz. You must ensure 2.4GHz is available on your new router. Third, port 1883 blocked — your new router may have stricter firewall settings, and port 1883 (used for MQTT communication) must be open for outbound traffic. Fix: reconnect via the Tesla app or directly to the TEG-xxx local WiFi, confirm your router is set to 2.4GHz or has dual-band, and power cycle both devices for 30 seconds.
Book
Gateway still offline after these steps?
If you have checked the LED status, verified your WiFi band (2.4GHz for Gateway 2), reconnected via the app and checked port 1883 in your router firewall, and the Gateway is still offline, the issue may be a Gateway hardware fault, a router configuration problem or a DNS issue. If the Gateway needs reconnecting to your WiFi, we can set it up on site, from £195: we connect it to your WiFi, set up your router, including a separate 2.4 GHz network if it needs one, and check it's reporting. If the signal doesn't reach, a WiFi extender is an extra £75, and we carry them with us. Independent from Tesla and your installer.
- Not affiliated with Tesla Inc
- No fix, no fee covers remote fixes. On-site work is quoted in writing before we start.
- On-site visits available across the UK
Service notice
We’re busier than ever. Thank you for your patience.
Due to unprecedented demand we’re currently only carrying out on-site work in Yorkshire, and replies are taking up to 7 days. Remote diagnostics continue for the whole UK as normal.
Every message is read and answered, so please don’t send it twice; that only slows the queue.
Ronald Director, Solar Tech Support
On-site: Yorkshire only, for now
Remote: UK-wide, as usual
Remote fix: £125 if we fix it, no charge if we don’t
Replies: within 7 days
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