Ispring UVF11A Installation And Maintenance Manual page 7

4) Insert the lamp into the pre-
installed quartz sleeve
7) UVF11A has 2 ports. Either one can be IN or OUT as long as water flow matches the arrow sign on the Smart Flow Sensor.
The flow sensor needs to be installed before the inlet. See the water flow direction shown by arrows in the following picture.
5) Attach the black rubber cap to
the end
- 6 -
6) Insert the stainless-steel UV
housing into the clips provided, then
mount the UV sanitizer on one of
the stages on the filter