For the last week or two there is a loud buzzing sound coming from the unit (like a transformer hum or poor earthing hum).
I have identified the hum only comes on when the lcd display backlight is on (so I can toggle the hum on/off by turning the alarm on/off).
Can anyone help me resolve this issue - Lumie folks if you have suggestions this would be greatly appreciated (you don't have an email address on your "Contact Us" page).
Is the sound setting on? as you say it is only active when the alarm is on
If so there will be a hash symbol in the display. with alarm off ("A" depressed) press "P" and scroll through to sound menu, them pres "+" or "-" until sound is on auto/off/perm.