Customer FAQs Discover answers to the most frequently asked questions from ADT customers with the click of a button. 1. Why can’t I dim my light? Check to make sure you are using only incandescent bulbs for all dimmable light modules. Compact Fluorescent light bulbs (CFL’s) are generally not dimmable. This also applies to the CFL bulbs used in round bulb sockets. LED bulbs can be dimmable and supported by newer Z-Wave dimming controls for energy efficiency usage.Also, there are two types of lamp modules – one that allows dimming and one that is strictly on/off. The best way to check if a plug-in module is a dimmer is to check the model number against the approved list.