Explanation:
The reason why your bulb is not working , is most likely because the housing containing the bulb is not "Clicking". There is a sensor on the inside cap that presses a metal handle that turns on the light. IF this is not depressed, there's a high possibility this is causing the UV bulb not to turn on . This should be the FIRST thing to check and should be an EASY fix, instead of getting a replacement bulb. IF this is not the case, please contact us and we can provide better video instructions for you, or even a replacement if you're withing the 6-month warranty period. These instructions are for CUV-109a and CUV-172a
VIDEO EXPLAINING HOW THE TWIST ON BULB WORKS :
VIDEO EXPLAINING HOW TO SCREW ON: