Hiya,
If you number the lights with 1 at the left, which number is flashing?
Thanks
It's a "time out heating " fault.
If the water isn't getting hot you'll need to check the heater. To do this you will need access to and be able to use a multimeter. Test the heater for continuity, if it's open circuit you'll need to replace it.
If OK, test the wiring from the control board in the door to the heater. If open circuit, trace the wires and repair the break.
If OK, you are left with the main control board in the door as the possible fault.
If the water is getting hot.
Check the thermister in the door hasn't come adrift from the corner of the dispenser.
Hope this helps.
Let me know how it goes or if you need more help.
Home Appliance Technician
Whitegoods engineer working for a multibranded national company in the UK.