Basic Troubleshooting

Gateway plugged in to service jack but…

…no LED at all

If the LED is always off, there either is no power or the firmware is wrong, corrupt or has a wrong setting.

  • No power on the Service jack -> Plug in a USB power adapter to the Wemos directly. The LED should start blinking now.
  • Buck missing or broken -> Plug in a USB power adapter to the Wemos directly. The LED should start blinking now.
  • You are shortcutting the bus or the jack. -> unplug the Gateway and wait 2 min before plugging it back in.
  • You are drawing too much current from the bus. -> Unplug the Gateway, remove all external components and and wait 2 min before plugging it back in.
  • No firmware or firmware update error -> Reload a stable firmware image.
  • LED is turned off in the firmware settings -> Log in to the web interface and turn it on.

…LED keeps blinking forever

If the LED keeps blinking forever this means it cannot find the EMS bus.

  • Boiler with no EMS bus -> The Gateway is only compatible with the EMS bus.
  • EMS wires not connected or faulty -> Reconnect the jack cable or otherwise connect the screw terminal of the Gateway to the thermostat wires.
  • The board is running in Serial mode -> This will be shown in the Telnet session and you can use ‘set serial off’ to disable it.

…LED turns solid but start blinking again after a while.

In this case the EMS bus was found at some point, but due to either intermittency problems the communication was lost.

  • Bus wires not connected properly -> Reconnect the EMS bus wires.
  • Perhaps the Wemos is not getting enough power and is rebooting. -> Remove external components and try again.

…LED is blinking or is solid but cannot connect to the web interface or with Telnet.

This is likely caused by network communication issues.

  • You are not connecting to the right IP or if using Telnet not on port 23 -> Change to the IP address of the Gateway and to port 23.
  • Your laptop (with Telnet) is not on the same network as the Gateway -> The Gateway should be on either your home network or it is in access point mode. In the latter case connect your laptop to the ‘ems-esp’ Wi-Fi network.

Gateway connects to home network but MQTT is not connected

There can be a range of issues.

  • Wrong IP -> Set the correct IP of your MQTT broker. This is not always the same IP address as your home automation system.
  • Wrong user/password -> Make sure the MQTT authentication is set right or not at all.
  • Wrong port -> the MQTT port is 1883 by default. If you need to change this you have to build the firmware yourself.
  • MQTT broker is not running -> Make sure the broker is running on the target machine.
  • MQTT broker is not installed -> Install a MQTT broker like Mosquitto on the target machine.

MQTT is connected but seemingly no response

  • You are listening or publishing to the wrong MQTT topics.

More troubleshooting

For more troubleshooting see Proddy’s EMS-ESP Wiki [1]. Or send me an email via the webshop.