Frequently Asked Questions How long does the Sonicare Sanitiser UV bulb last? No need to replace your entire Philips Sonicare Sanitiser when the bulb wears out. Find out if, when or whether you need to replace the UV light bulb? Two years warranty There is no specific working life for the UV bulb. It is warranted for two years. You can replace the bulb if it is necessary to do so. The bulb is available via the Philips on-line parts store.