flaspa1

Hello. I really am a novice regarding Hot Tubs. I have an Ultra Pure UPs350 ozonator with my Jacuzzi J-355 spa, approximately 4 years old. I just drained and refilled the tub. There are tiny bubbles coming out but I don't see any light in the Ozonator. Does this mean my ozonator is not working? Do I need to replace the entire thing? Does this unit have a replacement bulb or chip? I also noticed when they installed the Ozonator they did not do a Hartford Loop and am wondering if this might be a problem. Thanks anyone for the help.