Rimless Pan - Flushing?

The problem likely lies with the setup of the concealed cisterns or the connection to the toilet pans.

• Low Water Level Your toilet's cistern needs a specific volume of water delivered quickly to create a powerful, effective flush.If the water level is set too low, the flush will be weak. Manufacturers typically mark a fill line on the inside of the tank, usually about an inch below the overflow tube.The installer may have set the level too low, or the components may be misaligned;

The float mechanism inside the cistern needs to be adjusted to allow more water to fill the tank after each flush. This is a common fix for weak flushing;

• Improper Flush Valve Settings Dual-flush cisterns have adjustable flush valves to control the volume for both the full and reduced flush. It's possible the "full flush" setting on the valve itself is not correctly configured to release the full 6 liters.

The flush valve, which is the large component in the center of the cistern, can be adjusted. Often, a lever on the valve can be moved to change the water level for the flush.

• Flush Rod Adjustment For concealed cisterns operated by push buttons, the rods that connect the buttons to the internal flush mechanism must be the correct length. If they are not set correctly, pressing the button may not fully activate the flush mechanism, resulting in a weak or partial flush;

The flush rods can typically be screwed in or out to adjust their length. Tightening them may be all that is needed to fully engage the flush mechanism and provide a more powerful flush.

• Obstructed Flush Pipe: the pipe connecting the cistern to the toilet pan might be pushed too far into the back of the toilet, which may result in the obstruction of the water flow and a weak flush;

The pipe may need to be pulled back slightly to ensure there is no obstruction to the water flow.

• Cistern Height: The height of the concealed cistern may require adjustment, perhaps replacing the siphon. A cistern that is mounted too low may not provide enough gravitational force for the water to flush the bowl effectively.

• Component Compatibility While less likely, an installer might claim that the toilet pan and cistern are incompatible "eco items" that inherently have a poor flush.

Even with 6L flush, rimless toilets should clear the bowl. Check flush pipe size/position, flush valve operation, and water pressure. Ask installer to review or get a second opinion.

The problem with your new Nuie rimless toilets flushing incompletely, even with a full 6L flush, likely stems from an issue with the cistern's flush mechanism or the toilet bowl's design/plumbing. Several factors could be contributing to this, including a restricted flush inlet, a misaligned flush lever, or even a blockage within the toilet's trapway

If your Nuie rimless toilet isn't flushing the entire pan, the issue likely stems from a clog, a low water level, or a problem with the flapper or flush mechanism. Addressing these issues can restore proper flushing functionality.

Test water pressure: Have a plumber check if there’s sufficient water pressure going to the cistern.

Check cistern setup: Have the plumber double-check the cisterns to ensure they are installed correctly and functioning as they should.

Clean the jets: If the jets are clogged with limescale, descale them.

Check for clogs: Ensure that there are no blockages or issues with the waste pipes.

Contact the manufacturer: If everything else seems fine and the problem persists, it may be worth reaching out to Nuie or the installer to see if others have experienced the same issue with this model.

Since the problem is present in both toilets, it's more likely to be related to either the cisterns, water pressure, or the toilet design itself rather than being an isolated issue with installation.