One or both the UV Lamps are not lit when the unit it running. Check the Lamp Connector Plug to see if it’s connected properly. Water fouling has shorted the lamp connections. There could be a Bad UV Lamp. There could be a Bad Ballast.
The Green Indicator is not lit when pool system is on. There is no power to the UV-C 50 from the Power Source. Check circuit breaker at the power distribution box. Check for loose connections or wiring breaks in the lines. Indicator light may have burnt out.
