Installation Guide: Three Way Kitchen Taps

How to Connect 3 Way Kitchen Filter Taps & Under-Sink Pipework

A 3 Way Kitchen Tap (also known as a Triflow or Filtered Water Comfort Tap) is an advanced multi-channel faucet designed to deliver standard Mains Hot, Mains Cold, and Independent Filtered Drinking Water from a single countertop footprint.

By integrating a dedicated internal waterway, it eliminates the need to drill a second hole in your premium wooden or granite worktop for a separate drinking water dispenser. This guide covers the essential plumbing configurations required to achieve a flawless, leak-free installation under UK domestic water systems.

1. Under-Sink Anatomy & Package Checklist

Before removing your old kitchen mixer, unpack your 3 Way tap and identify the triple-line inlet arrangement at the base of the faucet body:

• Hot Water Inlet: Standard connection (usually left).
• Cold Water Inlet: Standard connection (usually right).
• Filtered Drinking Water Inlet: Dedicated narrow waterway leading to an independent inner nozzle.
• Flexible Inbound Tails: The package includes 3x extended flexible stainless steel braided hoses. Two are standard G1/2" or G3/8" connectors for hot/cold, and one is a dedicated adapter for drinking water lines.
• The John Guest / Push-Fit Adapter: A special compression adapter converting the filtered tail down to standard UK 1/4" or 3/8" plastic John Guest speedfit tubing (the standard connection size for Under-Sink water filter cartridges, reverse osmosis systems, or water softeners).

2. Technical Compatibility Specs

Feature	UK Standard Specification	Installation Requirement
Countertop Hole Size	Standard Ø35mm	Fits all standard UK ceramic, stainless steel, and composite sinks.
Maximum Bench Thickness	Up to 40mm	Compatible with solid timber, marble, and quartz worktops (includes extended threaded shaft).
Minimum Water Pressure	0.5 Bar (Recommended 1.0 Bar+)	High-pressure systems (Combi-boilers) are optimal. Gravity-fed low pressure may require a pump.

🛠️ Step-by-Step Installation & Line Routing

Step 1: Pre-Assemble the Tails (The Triple-Hose Trick)

Because a 3 Way tap requires threading three separate hoses through a tight 35mm countertop hole, you must install them in a specific order:

1. Hand-tighten the Filtered Water flexible tail into the deepest central recess of the tap base first. Do not use tools; hand-tightening is sufficient to compress the internal O-ring.
2. Next, screw in the Hot and Cold flexible tails into their respective ports.
3. Thread all three tails down through the rubber washer, brass retaining plate, and the worktop mounting hole carefully.

Step 2: Securing the Tap Base

• From underneath the sink, slide the heavy-duty fixing nut up over the three braided tails.
• Hand-tighten the nut against the underside of the sink or wooden worktop.
• Use a box spanner to firmly lock down the assembly. Ensure the tap is perfectly aligned on top before full torque is applied.

Step 3: Connecting Hot & Cold Mains (G1/2 Specifications)

• Connect the Hot and Cold flexible tails directly to your under-sink isolation valves (service valves).
• If your tails are G3/8" and your UK isolation valves are standard 15mm compression fittings, ensure you use the included G3/8" to 15mm adapters alongside professional thread-seal tape (PTFE) to prevent slow leaks.

Step 4: Hooking Up the Filtration System (The Pure Line)

This is the most critical step for 3 Way taps. Do not connect this line directly to the cold mains supply!

1. Take the plastic water output tube (usually 1/4" white/blue PE tubing) coming out of your under-sink water filter kit.
2. Push the end of the plastic tube firmly into the provided John Guest push-fit adapter until it clicks into place.
3. Connect the other end of the adapter to the tap’s dedicated drinking water flexible tail.
4. Secure the push-fit connection with a locking clip (blue collet clip) to guarantee absolute water containment.

4. Post-Installation Testing & Flushing

1. Isolate the Filter Line: Keep the filtration kit turned off initially. Open the main hot and cold isolation valves to test standard mixing water. Check for any weeping around the threads.
2. Flush the Mains Lines: Run hot and cold water for 60 seconds to clear out air pockets.
3. Engage the Pure Filter Channel: Turn on your water filter system's feed valve. Rotate the dedicated drinking water handle on your tap.
4. The Carbon Flush Notice: Allow the pure drinking water to run for 2-3 minutes. If you have just installed a new carbon water filter block, the water will initially look dark or cloudy. Run it until it flows crystal clear and is perfectly tasteless.

⚠️ Crucial Maintenance Notes

• Never Use Aggressive Cleaners: To preserve the premium finish (especially our Antique Brass or Matte Black variants), clean only with mild soapy water and a microfiber cloth.
• Check Cartridges Annually: If you notice the filtered water flow rate dropping significantly while mains cold water remains normal, it indicates your under-sink filter system cartridge is clogged and needs replacing, not the tap valve itself.

Related Products

For a full 3 Way Kitchen Taps, please visit our product catalog:

Three Way Kitchen Taps - UKTaps Collection