When UV Needs TLC

Users won't notice much of a difference in the longevity of 300 watt and 400 watt lamps, but life cycles vary highly between 400 watt lamps, which can last 1,500 hours, and 800 watt lamps, which may burn out in 800 hours, depending on cooling system capabilities, Kershner points out.

UV systems' key electrical component, the ballast, primarily fails due to excess heat, Rose states. Proper ventilation in the main electrical cabinet can help keep replacement at bay, which can cost $3,000. If there is a loud buzzing coming from the ballast, 30 to 60 days of life remain, he notes.