What do the lights on my Openreach modem / optical network terminator mean?

What do the lights mean?

Modem power light is flashing green

Modem DSL light is off

Modem DSL light is flashing green

Modem LAN1 light is off

Modem DSL light is steady green & the LAN1 light is flashing green

Optical network terminator PON or optical light is flashing green

Optical network terminator PORT1 light is off

Optical network terminator PON light is green, LOS light is off or the optical light is green

Optical network terminator PON light is off, LOS or optical light is red

What do the lights mean?


Openreach modem lights Openreach optical network terminator lights What's happening
Power off Power off There's a problem with your power supply.
Power flashing green N/A Modem is restarting.
DSL off N/A Broadband isn't working.
DSL flashing green PON or Optical flashing green Modem is restarting.
LAN1 off PORT1 off Modem can't detect Hub.
DSL steady green
LAN1 green
PON green
LOS is off or Optical is green
Modem is connected to broadband & your Hub & both are working.
N/A PON off
LOS or Optical is red
Broadband isn't working.

Back to top


None of the lights are on

  1. Check Power On/Off button is in the On position.
  2. Switch off and unplug power.
  3. Check the power cable is correctly inserted.
  4. Check mains power is working.
  5. Plug power cable into mains and turn on.
  6. Wait a couple of minutes for the modem to restart.

Back to top


Openreach modem power light is flashing green

This means that your modem is restarting.

Back to top


Openreach modem DSL light is off

This means that broadband isn't working. Check the following:

  1. The DSL cable is plugged into the DSL socket on the back of the modem and into the engineer installed wall socket.
  2. If you're using an extension socket, check that this is also plugged in.
  3. Restart your modem.

Back to top


Openreach modem DSL light is flashing green

This means that the modem is restarting. Wait until the light is steady green, this can take a few minutes.

Back to top


Openreach modem LAN1 light is off

This means that the modem can't detect the Hub.

  1. Check that your broadband cable is plugged in between the LAN1 socket on your modem and the red Infinity socket on your Hub.
  2. Check that your Hubs power light is blue.
  3. Restart your modem.
  4. Now restart your Hub by pressing and releasing the restart button on the side of the Hub.

Back to top


Openreach modem DSL light is steady green & the LAN1 light is flashing green

Your modem is connected to broadband and your Hub, and is working.

Back to top


Openreach optical network terminator PON or optical light is flashing green

This means that the modem is restarting. Wait until the light is steady green, this can take a few minutes.

Back to top


Openreach optical network terminator PORT1 light is off

This means that the modem can't detect the Hub.

  1. Check that your broadband cable is plugged in between the LAN1 socket on your modem and the red Infinity socket on your Hub.
  2. Check that your Hubs power light is blue.
  3. Restart your modem.
  4. Now restart your Hub by pressing and releasing the restart button on the side of the Hub.

Back to top


Openreach optical network terminator PON light is green, LOS light is off or the optical light is green

Your modem is connected to broadband and your Hub, and is working.

Back to top


Openreach optical network terminator PON light is off, LOS or optical light is red

Broadband isn't working. Check that your fibre cable is firmly plugged in and isn't damaged.

Artboard 1 copy 2 Contact us


Chat online, call or email us.

Contact us