My home’s ultra-violet water purifier gives off a steady buzzing noise. What can I do to stop it?

Water purifiers use ultraviolet lamps to zap germs. As with fluorescent bulbs, it’s normal for a purifier light to give off a low hum. That said, sometimes a hum is created by the failure of the bulb or its ballast, which regulates power. To determine if your noise is a problem – and to avoid replacing parts that might not need replacing – check the owner’s manual for the longevity of the system components. If the bulb or ballast is nearing the end of its life span, go ahead and replace it. The other culprit could be loose components. Tighten any screws on the purifier or any apparatus mounting it to the wall. With a few turns of the screwdriver, quiet will be restored.