sustaining voltage and zero voltage across the bulb sustaining voltage indicates that the lamp is functioning properly line voltage indicates that the bulb is burned out broken or missing zero voltage indicates that the starter is shorted out or that power is interrupted the bulb status monitor circuit of the present invention would be included in a water treatment system of the type illustrated in fig1 and generally designated 30 the line connections illustrated between the blocks of fig1 are fluid connections permitting water flow through the treatment system generally speaking the water treatment system is connected to a potable water supply 32 and includes a valve 34 for selectively routing water either directly to the tap discharge 36 or to the filter and sterilization units 38 and 40 respectively the valve may be of the type illustrated in copending application ser no 07 977 161 filed nov 16 1992 and entitled faucet diverter valve in the water treatment system 30 the water can be sent directly to the tap discharge 36 by putting the valve 34 in a first manually selected position alternatively the valve 34 can be placed in a second manually selected position where the water is routed sequentially through the filter 38 and the sterilization unit 40 before being discharged from the tap at 36 the filter 38 is preferably a carbon activated filter the uv sterilization unit includes a water chamber container or passageway.