A reverse osmosis system gives you clean drinking water from a dedicated faucet in the kitchen. You can install it yourself in 1.5–2 hours: everything connects with plastic tubing and push-fit fittings, no soldering needed.

What the diagram shows

1 — pre-filter housings (sediment and carbon), 2 — the reverse osmosis membrane, 3 — the storage tank, 4 — the separate faucet for purified water.

Before you start

  • Inlet pressure must be at least 2.5–3 bar. Below that the membrane produces little water and you will need a booster pump.
  • Space under the sink for an 8–12 L tank and the filter block.
  • A drill bit for the faucet hole (usually 12 mm) in the sink or worktop.

Step by step

  1. Shut off the cold water and release the pressure by opening a tap.
  2. Fit the feed adapter to the cold water line under the sink and connect the system inlet tube to it.
  3. Clamp the drain saddle onto the sink waste pipe above the trap. The membrane flushes salt-laden water through it.
  4. Install the faucet on the sink or in a hole in the worktop.
  5. Fix the filter block to the cabinet wall and place the tank.
  6. Connect the tubes: inlet, drain, tank, faucet. Push each tube all the way in; remove the locking clip only to disconnect.
  7. Turn the water on and check every joint for leaks.

First start-up

Drain the first full tank — this flushes the carbon filters and the membrane preservative. The air pressure in the empty tank should be 0.4–0.5 bar: check it if the tank holds too little water.

Replace the pre-filters every 3–6 months, the post-filter once a year and the membrane every 2–3 years. If the pre-filters are not changed on time, the membrane clogs much sooner.

Replacement tanks and parts are in our reverse osmosis tanks section.