Your UV or Ultraviolet Disinfection System is beeping because there is something wrong, so one of these things has put it into alarm.
1) The timer has triggered because it has been about a year since the lamp was changed and now it is time for a new one.
2) You replaced the lamp but didn’t reset the timer.
3) The lamp burned out or is defective.
4) The controller is defective.
5) You have a monitored system and the sensor has triggered the alarm because your water quality is below the acceptable level.
6) There was a power failure and the ballast triggered the alarm when the power came back on.
7) You have an Excelight or UV Dynamics UV and the ballast wasn’t in alarm mode when you tried to reset the ballast.

You need to realize that the alarm is on for a reason and it maybe that, if you have a monitored UV system, the alarm is telling you that your water has become so discoloured or murky that the UV will not be able to kill any bacteria present. Your sensor may also be dirty, so check that first.

The next thing to do, assuming your ballast does not have an LED readout with count down timer, is to push the button on the front of the ballast to see if that stops the beeping. If it does, it means you’re nearing the end of the lamps 9,000 hours or one year of service life and it’s time to replace. This will shut it up for one week, but if you don’t replace the lamp after one week it will start beeping again to remind you. After one month you will not be able to stop the beeping unless you replace the lamp.

Resetting the timer varies by manufacturer and you can check out my other UV videos to show you how to do it for your brand. But generally, the lamp change reminder timer is reset by disconnecting the UV power source from the AC supply, waiting for at least fifteen seconds and reconnecting to the AC supply with the timer button depressed. With UV Dynamics systems the UV power source (or ballast) will emit a solid three-second beep indicating that the reset was successful. You can confirm that it has reset by pushing and releasing the button and counting the number of times the red indicator light flashes, if it flashes 12 times, that means the timer is reset and there are 12 months of life left before the lamp needs to be replaced.

By the way, if your Excelight or UV Dynamics UV system is not in alarm mode when you replace the lamp you will not be able to reset the timer so you need to put it into alarm mode by unplugging the unit for 5 minutes, removing the old lamp, and with the old lamp removed, plug the ballast back in until it starts beeping. Then unplug and install the new UV lamp and reset.

Occasionally, after a power failure, you may get beeping, unplug the controller, wait one minute and plug it back in, if that doesn’t fix it try to reset the ballast.


If it’s not your water quality, the sensor is clean (if you have one) you’ve replaced the lamp, reset the timer and it still keeps beeping, the ballast is faulty and needs replacement.