Karofi Under Counter RO Installation Guides

• Pre-installation checklist
• Tools and components required
• Step-by-step installation instructions
• Cartridge placement order
• Initial flushing procedure (membrane left out)
• RO membrane installation steps
• Final start-up (tank fill & purge)
• Ongoing maintenance and troubleshooting

Tools required

• Adjustable spanner or shifting wrench
• Electric drill with 6mm drill bit for drain hole & suitable drill bit or hole saw (for faucet if needed)
• PTFE (Teflon) tape
• Bucket and cloth for spillage
• 1/4" RO-compatible pressure-limiting valve (not included in Karofi kits)

Pre-installation checks

• Cold water supply accessible beneath sink
• Adequate space for RO unit and storage tank
• Water pressure 2.8–6.0 bar; temperature 5–38 °C
• Drain line accessible for waste water outlet
• Install only on cold municipal or suitably pre-treated water

Important: Do not install directly on untreated borehole water with iron, manganese or excessive hardness without suitable pre-filtration.

NOTE: If supply water pressure is above 6.0 Bar we recommend installing a 1/4" in-line pressure regulator valve on the supply to the RO to prevent damage to the housings. 

Step 1: Connect the feed water adapter

• Turn off the cold water supply valve under the sink & disconnect the flexi-hose off the valve.
• Install the feed Female x Male coupler with 1/4" valve on the cold line.
• Re-install the flexi-hose to the Male side of the coupler just installed.
• Apply PTFE tape to all threaded connections.
• Connect the white 1/4" tubing to the 1/4" inlet valve just installed.
• Close the 1/4" and reopen the cold water supply valve under the sink to check for leaks.

Step 2: Prepare the filter cartridges

• Unscrew all three 10" pre-filter housings with the provided spanner.
• Remove the plastic shrink-wrapping from each cartridge.
• Reinstall the cartridges in the correct order and hand-tighten housings.

Note: Leave the RO membrane out of its housing until the first system flush is completed to prevent carbon fines clogging the membrane.

Step 3: Mount the RO faucet

• If no spare hole, drill a ±12 mm hole in a suitable position.
• Install faucet with supplied washers and locknut.
• Connect the Blue 1/4" blue tubing from RO T33 Post Carbon cartridge outlet to faucet.

Step 4: Install the drain saddle

• Select a position on a (ideally vertical) 40mm drain pipe section after the U-Trap.
• Drill a 6 mm hole, align saddle and tighten firmly.
• Insert a short piece of the Yellow 1/4" drain line tubing into the saddle.
• Connect the other end of the Yellow drain line tubing to the single side of the tubing splitter fitting.
• Insert another piece of the Yellow tubing to the other side of the splitter fitting, connecting it the to Flow Restrictor outlet on the RO unit.
  

Step 5: Connect the storage tank

• Wrap tank thread with PTFE tape and attach tank valve to the top of the tank.
• Connect the Blue 1/4" tubing from Tee on the inlet of the Post Carbon cartridge on top of the RO system to the short side of the tank valve.
• Keep the tank valve OFF during the first flush.
• Connect Yellow tubing to the other long side of the tank valve, then the other end of the tube to the other open side of the splitter fitting on the drain line. This is for over pressuring release.

Step 6: Position the RO system

• Wall-mount the bracket or stand upright beneath the sink.
• Ensure clear access to pre-filters and membrane housing.

Initial flushing (membrane not installed)

• Open the 1/4" cold water feed valve.
• If fitted with a booster pump, power the system ON.
• Open the RO faucet and run for at least 10 minutes to remove carbon fines and air out of the system.
• Keep the faucet open throughout this stage. 

Install the RO membrane (After Flushing)

• Switch OFF the system, pump (if fitted) and water supply/feed.
• Unscrew the RO membrane housing cap.
• Insert the membrane: the male pipe end goes in first so it slides into the internal port; the rubber O-ring end faces the cap (goes in last).
• Ensure full seating so the cap closes properly, then tighten securely by hand.

Post-membrane installation flush

• Turn the system and water feed back ON.
• Open the RO faucet and flush for a further 5 minutes.

Cartridge order (front-to-back view)

1. Sediment Filter (5 µm) – removes sand, silt and rust
2. Granular Activated Carbon GAC – reduces chlorine, taste, odour, VOCs
3. Carbon Block Filter – reduces chlorine, taste, odour, VOCs
4. RO Membrane – reduces dissolved salts, heavy metals, microorganisms
5. Post Carbon Remineralisation (T33) – final taste polishing

Final system start-up

• Close the faucet and turn the storage tank valve ON.
• Let the tank fill fully, then drain it through the faucet.
• Repeat a full tank fill and drain once before drinking.

Ongoing maintenance

• Replace pre-filters (sediment + carbon) every 6–12 months.
• Replace RO membrane every 24–36 months (confirm via TDS readings or slow to no flow).
• Replace post-carbon/polishing filter every 12 months.
• Sanitise system at each filter change.
• Flush for 5 minutes after any filter change.
• Remember to remove the RO Membrane if only changing the 10" Pre filters.

Troubleshooting

Use the diagrams below as a visual reference (with/without pump variants).