The D-D RO Units are supplied with 2m each of 3 coloured pipes which should be connected to the unit on assembly. To make this easy we fit 3 short sections of pipe into the unit for identification of the ports.

  • White - Water feed
  • Orange - Waste water - concentrate ( restrictor to be fitted to this pipe)
  • Blue - Pure water - permeate

Occasionally the blue and orange pipes are fitted reversed and this results in very little water through the orange wastepipe and most coming through the blue pipe.


A simple check to ensure your unit is piped correctly is as follows:

  1. Connect the white pipe to the mains supply and to the clear pod of the RO unit.
  2. Connect the blue and orange pipes as you believe is correct and at this stage do not fit the flow restrictor.
  3. Switch on the water to the unit and watch the flow from the 2 coloured pipes. One will have a much higher flow than the other and this is the waste pipe which should be orange leaving the other blue. If this is not correct then swap the 2 pipes over.
  4. Fit the flow restrictor to the orange pipe and the flow will reduce and increase from the blue pipe. Do not expect a huge flow from the blue pipe as during normal operation this will be only a dribble depending on the temperature and pressure of the water.
  5. Ensure that the flow restrictor valve is at 90 degrees to the firection of the flow to restrict it and observe the flushing mode when it is inline.
  6. Flush the membrane for a couple of hours to remove the antibacterial chemicals that the membranes are packed with.