Interflush Fitting Instructions


  • Remove cistern lid and use as parts tray.
  • Remove any cistern displacement devices i.e. Hippobags.
  • Set the water level to the marked line on the back of the cistern.
  • Ensure that the back nut on the flush handle is tight.
  • Ensure that the siphon is functioning correctly by testing the flush.

1. Check and familiarise yourself with the parts. (see fig. 1)

2. See where the parts fit by referring to the ‘completed installation’ image (see fig. 8). Now is a good time to watch the fitting video.

3. Clip or slide adaptor on to spindle – make sure that the gap on the adaptor faces away from the siphon and that the ridged band of the adaptor is facing the back of the cistern (see fig. 3).

Note: The square adaptor fits two sizes in one. The larger and obvious square is for longer and thicker spindles, 9mm, used on boxed in cisterns. The smaller square, formed by the notches, 7mm, is for smaller standard size spindles. 

4. Twist  the adaptor to engage the edges of the spindle into the notches on the adaptor.

5. Fold spindle clamp around adaptor, with swivel catch on the top and the gap facing away from the siphon. Lock in place with long clamp screw (see fig. 4).

6. Mark centre line on top of siphon, from left to right not back to front (see fig. 5).

7. Place baseplate on the flattest part of the siphon cap with folding clamp arm nearest to you. Locate large central hole over drawn centre line and mark through the hole with a pen onto centre line (see fig.6 ).

8. Using a cordless drill and the 8mm drill bit supplied, drill through the siphon cap where marked.

Note: Do not remove the plastic tube on the drill bit, this prevents drilling too far.

9. Insert end of rotor into housing at rear of baseplate. Fold clamp arm over and secure with two screws. Check the rotor and spring lever to ensure that they move freely (see fig. 7).

10. Straighten out the connector line by bending it over your fingers. Pass the coarse end of the connector line up and through the hole in the rotor and press into matching recesses. Twist swivel catch to lock in place (see fig. 8).

11. Place baseplate on siphon cap, locating protruding boss on the underside in the drilled hole. Rotate baseplate into correct alignment so the connector line runs in a straight line to the spindle clamp (see fig. 9).

12. Holding the baseplate firmly in position throughout, drill all four fixing holes using the 4mm drill bit supplied. Locate the drill bit in the baseplate holes and drill through the siphon cap. Lift off and clear away any debris.

13. Check the fasteners so that the barbed nuts are only finger tight and the sleeve is not splayed out.

Note: A spare is provided in case one is dropped in the cistern. These work like rawlbolts when screw tightened in position.

14. Align baseplate with drilled holes and insert the four fasteners that have square heads in the recesses of the baseplate. Push fully in with the screwdriver. If one will not go in, pass the drill through again (see fig.10).

15. Pushing down on the baseplate, tighten the four fastener screws until the heads just start to sink into the plastic sleeve (see fig. 11).

Note: The foam neoprene gasket forms an airtight seal over any raised printing or slight curvature of the siphon cap.

Final Adjustment

Set the connector line to get the spring in the middle. Adjust the connector line tension at the spindle clamp end so that the tip of the spring lever is just about to touch the upstanding rib on the baseplate. Turn swivel catch to lock in place. Clip off excess connector line leaving about 2cm spare at each end (see fig. 12).

TEST FLUSH. Flushing should continue when the handle is held down (spring lever fully bent, air-break closed). Flushing should stop immediately when the handle is released or raised (spring lever flat again, air-break open). If needed, adjust connector line tension a notch at a time until correct operation is obtained. Lock swivel catch in place by tightening the screw down (see fig. 13).

Replace cistern lid and display instruction label in a prominent place.

 If you have any problems, please do not hesitate to contact us.