What to do when C-Bus dimmer channel will not turn off ?
First of all check that the programming is correct.
If using LED lights, the LED may stay on when the channel is off, this is due to the leakage current being enough to power the LED, use of a 31LCDA may resolve this issue.
If using Halogen and the channel will not turn off, there may be damage to the electronics on this channel - Electricians only to perform this check, disconnect the Active's , Neutral and Earth from the unit, remove the cable for the load on that channel then with a multimeter check between the Neutral and that suspect channel output, if you see a low resistance the Triac has shorted.
Advise not to use this channel and label as faulty, other channels on this dimmer should still be ok to use as per normal, alternatively you could return this unit for a quote on repair, note a repair may not be possible.