V-Pro LED dimmer problem

[Ansgar]

First ever post on here - hello everyone

I've just installed varilight V-Pro LED dimmers in two bedrooms in my flat, the LEDs installed in both rooms are the same and I've wired both dimmer switches the same way.

Problem: the dimmer in one bedroom works, but in the other room the light flickers and turning the dimmer has no effect. However, it works again when I unscrew the face plate and pull it off the wall.

Any ideas? The back box is quite full so could there be interference from any of the other wires?

 

[PrenticeBoyofDerry]

First make sure you have good secure contact of all conductors in their appropriate terminals, double check no conductor cores are exposed outside of terminals/connectors and no conductor insulation is trapped within them.
I assume the LEDs are compatible with the dimmer?

 

[Echo the husky]

Could you post some photos of the wiring, it may show a problem?

 

[Ansgar]

Thank you both! After PrenticeBoy's post, I checked the connections. In particular, it seemed that the neutral wires in the back box were getting squashed. I moved them to another corner where there was more space. Now the dimmer works...