Over time, the end of a UV sensor may become stained, which will lower the UV intensity readings displayed on the controller. A UV sensor should be cleaned at least once per year, as well as if the UV intensity on the controller is decreasing significantly. Follow the steps below to clean a UV sensor.

1. If a bypass assembly is installed, shut the inlet valve off to prevent water flow through the system. Otherwise, turn off the main water inlet valve (and/or turn off the water pump).
2. Disconnect the power cord of UV system from electrical outlet.
3. Release water pressure by opening a downstream faucet and then close the outlet shut-off valve (if any). If there is no outlet shut-off valve, expect water to drain from the system.
4. Place something under the reactor to catch any water that may come out of the reactor during the removal of the UV sensor.
5. Unscrew (counterclockwise) sensor nut from the reactor and pull the sensor slowly out of the sensor port.
6. Holding the sensor in your hand wipe the flat portion (sensor face) of the sensor with isopropyl alcohol using a clean lint-free cloth.
7. Reinstall the UV sensor and screw the sensor nut back on counterclockwise.

The best way to ensure UV sensors are operating at peak performance is to ensure the water quality parameters fall within the specifications below.

Hardness:                        <7 gpg (120 mg/L)

Iron (Fe):                          <0.3 ppm (0.3 mg/L)

Manganese (Mn):          <0.05 ppm (0.05 mg/L)

Turbidity:                         < 1 NTU

Tannins (organics):        <0.1 ppm (0.1 mg/L)

UVT (transmittance):    >85%