How to Reconnect a GoodWe ESA to Wi-Fi After Changing Router or Password
Scope: This homeowner guide applies to a current GoodWe ESA 3-10 kW system using the
WiFi/LAN Kit-20smart dongle documented in GoodWe's ESA User Manual V1.7. App screens can vary by SEMS+ version, account permissions and device model. This guide changes monitoring-network details only. Do not open the inverter, unplug the dongle, factory-reset it, or change safety code, grid, battery or operating-mode settings. If your dongle has another model code, use its exact official manual or call your installer.
The direct answer
After a router, Wi-Fi name or password change, the GoodWe smart dongle may still be trying to join the old network. For the current WiFi/LAN Kit-20, use the official SEMS+ app to make a local Bluetooth connection, select the new 2.4 GHz Wi-Fi network and enter its current password. Then use the dongle's communication light to check whether it has reached the router and GoodWe's server.
The important safety boundary is simple: change only the WLAN network details. If SEMS+ presents commissioning choices such as safety code, grid settings or working mode, leave them unchanged. If the app will not let you proceed without recommissioning the system, stop and ask the installer.
Before you start: confirm the hardware
GoodWe's current ESA manual lists the WiFi/LAN Kit-20 for Wi-Fi, LAN and Bluetooth communication. Its local Bluetooth signal appears in SEMS+ with a name beginning WLA- followed by device-identifying characters. The exact name is matched using the serial number.
Older GoodWe communication devices can use a different process, so do not apply legacy or generic setup instructions to this system.
Collect these details without removing or moving anything:
- inverter model code from the external label;
- smart dongle model, if its label is plainly visible;
- inverter or dongle serial number used to identify the local signal;
- your new Wi-Fi network name and password; and
- your existing SEMS+ account details.
Keep serial numbers, QR codes, verification codes and passwords private. Do not post them in a public support forum or photograph.
Safe reconnection steps
1. Check that this is a monitoring problem
Look at the external indicators from a safe position. A red flashing system indication means a system fault; an unlit operation indication can mean the inverter is powered off. In either case, stop and call the installer. If operation appears normal but SEMS+ is offline, continue without touching covers, isolators or wiring.
2. Check the new router
The WiFi/LAN Kit-20 specification lists IEEE 802.11 b/g/n at 2.4 GHz. Confirm that the router is providing a 2.4 GHz Wi-Fi service and that you know the exact network name and current password. A router can support other bands as well; the relevant point is that a compatible 2.4 GHz network must be available to the dongle.
Test the new internet connection with your phone while standing near the installation. This does not prove the dongle is connected, but it rules out a general broadband outage.
3. Update and open SEMS+
Use the official SEMS+ app from your phone's normal app store. GoodWe's current app manual notes that interfaces may change between versions, and that available features differ by account role and device model.
Log in to the existing account containing your Solarboss installation. Do not create a duplicate power station.
4. Enable the dongle's temporary Bluetooth signal
On the WiFi/LAN Kit-20, double-click the Reload button quickly. GoodWe says this enables Bluetooth for five minutes. The dongle's communication light changes to a single-blink pattern while it waits for the app.
Do not press and hold the button. The manual says a long hold can restore the smart dongle to factory settings, including passwords and network configuration. Factory reset is outside this homeowner guide and can make recovery more complicated.
If the Reload button is not clearly identifiable, or the dongle is not safely reachable from floor level, stop and ask the installer to reconnect it.
5. Connect locally in SEMS+
In the current SEMS+ app manual, the local connection path is:
- Open Service.
- Choose Local Access.
- Select the Bluetooth tab for the
WiFi/LAN Kit-20. - Tap Search for Devices or refresh the list.
- Select the
WLA-...signal that matches the serial number of your equipment.
The connection names and labels can differ in later app releases, so follow the equivalent local-access prompts if the wording has changed. If the app asks for a local-access password, use the credential provided for your installation. Do not try passwords copied from an online guide, and do not share the password in screenshots.
6. Change only the WLAN details
Once connected locally, SEMS+ provides access to system cards and device settings. Open the communication-module or smart-dongle settings and find the WLAN network selection. Choose the actual new Wi-Fi network and enter its current password exactly.
GoodWe's app manual describes the WLAN setting as selecting the Wi-Fi network the device will use to communicate with the router or switch. Depending on app version, this may appear inside a quick-configuration flow.
In Quick Configuration, change only the network information. Leave the safety code, country, working mode, export limits, battery settings, protection values and firmware unchanged.
If the app does not clearly separate the network step from commissioned settings, exit without saving and contact the installer.
7. Save and read the communication light
Allow a few minutes for the new connection to establish. The current ESA manual gives these WiFi/LAN Kit-20 communication-light meanings:
- Steady: communication is normal in Wi-Fi or LAN mode.
- Single blink: Bluetooth is enabled and waiting for the app.
- Two blinks: the dongle is not connected to the router.
- Four blinks: it is communicating with the router but is not connected to the server.
- Six blinks: it is identifying connected devices.
- Off: it is resetting or is not powered.
Do not judge a blink pattern from a single instant. Watch long enough to identify the repeating count, then record a short video for support if the issue remains.
8. Confirm SEMS+ returns online
Reopen your existing power station and check the current device status and dongle light together. A historical graph point does not prove the live connection is restored.
If it still will not connect
Use the light pattern to narrow the problem without touching the electrical installation.
Two blinks: not connected to the router
Check that the configured network name, encryption method and password match the router. If they do, restart the router using its normal controls. GoodWe also advises moving the router closer or adding a repeater for a weak signal. Do not move the inverter or battery, and do not factory-reset the dongle.
Four blinks: router connected, server not reached
The local router connection exists but the dongle has not reached the server. Check general internet access and restart the router once. Do not change inverter settings; if four blinks continue, contact the installer or GoodWe support.
Dongle power light off
The power light should be steady when the communication stick is powered. If it is off, do not unplug, reseat or dismantle the dongle. Photograph the indicators and call the installer.
The app cannot find the WLA-... signal
Use a quick double-click, search within the five-minute Bluetooth window, refresh the list and confirm another phone is not connected. If the signal remains absent, let the installer verify the dongle model, power and software.
Stop and call your installer when
Stop the homeowner checks if:
- the inverter shows a red flashing fault indication;
- the dongle power light is off;
- you cannot confirm the dongle is a
WiFi/LAN Kit-20; - the app asks you to alter safety, grid, battery, protection or operating-mode settings;
- the equipment must be opened, unplugged, moved or electrically tested;
- a cable, enclosure or connector looks damaged;
- you accidentally held Reload long enough to start a factory reset;
- two-blink or four-blink status continues after the safe router and credential checks; or
- you do not have the correct account or installation-specific local-access credential.
Information to collect for support
Send the installer:
- inverter model and serial number;
- dongle model and visible identifier;
- phone type and SEMS+ app version;
- router make/model and whether 2.4 GHz Wi-Fi is enabled;
- the exact repeating light pattern;
- the time the router or password changed;
- whether other devices have working internet;
- a screenshot of the SEMS+ offline message with private details obscured; and
- a short video of the external lights.
Do not send the Wi-Fi password, local-access password, account password, verification code or a readable QR code.
For details of the installed offer, see the Solarboss GoodWe ESA 5 kW and 8 kWh system.
Frequently asked questions
Does the GoodWe WiFi/LAN Kit-20 use 5 GHz Wi-Fi?
GoodWe's current specification lists 802.11 b/g/n at 2.4 GHz. Ensure a compatible 2.4 GHz service is available from the router.
Should I factory-reset the dongle?
No. This guide deliberately avoids factory reset. GoodWe says a long Reload-button hold restores factory settings, including network and password information. Ask the installer before considering it.
Why does the light blink four times if my Wi-Fi works?
Four blinks mean the dongle is communicating with the router but not connected to the server. That is different from the two-blink “not connected to router” state.