This problem may have various causes:

1. The cover of the UV chamber may be open. If it is open, close it.
2. The UV lamp may be dirty. Clean the UV lamp.
3. If 1 and 2 have not helped and the UV indicator remains on, an error has occurred inside the UV chamber. Try to solve this error by resetting the pure water dispenser. Unplug the appliance from the mains for approximately 10 sec.
4. If this doesn’t solve the problem and the UV indicator continues to be on, please contact Philips Consumer Care. You can find the phone number of the Philips Consumer Care Center in your country on the support page under ‘Contact’ or ‘Customer Service