Installing Under-Sink Waste Systems: Suitable Replacements for Nobilia and Alno Waste Sorting Units

June 9, 2026

A built-in waste system is a mechanical pull-out unit mounted on drawer runners inside the sink base unit, integrating waste separation directly into the furniture carcass.

When the waste separation system in an existing kitchen from manufacturers such as Nobilia or Alno jams, the runners rub, or the plastic has fatigued after years of use, a replacement is due. For the joiner or experienced fitter, the primary question is not sourcing an exact original spare part from the kitchen manufacturer, but finding a technically suitable alternative. As long as the installation dimensions, internal carcass width, and door hinge type are taken into account, defective units can easily be replaced with standardised fitting hardware. This guide defines the technical criteria for selecting and fitting a compatible under-sink waste system.

Key Buying Criteria for Waste Systems

When replacing waste sorting units or defective kitchen cabinet pull-outs, precise technical specifications matter. The mechanism must fit into the available space and reliably support the daily dynamic load of wet, heavy household waste.

Cabinet Width and Internal Clearance

The industry designs kitchen cabinets according to standard grid dimensions. The standard external dimensions for a sink base cabinet are typically 400 mm, 450 mm, 500 mm, or 600 mm. However, the decisive factor for installing the waste system is the internal width (clearance). With a typical side panel thickness of 16 mm or 19 mm, a 600 mm wide cabinet provides an internal clearance of 568 mm or 562 mm respectively. Hardware manufacturers always state the external cabinet width for which a system is designed, as frame constructions can often be adapted to different panel thicknesses using spacers.

Installation Depth and Trap Obstructions

The sink base cabinet is the most congested space in the kitchen. Service valves, flexible hoses, water heaters, and particularly the waste trap block space towards the rear and top. Measure the maximum available installation depth from the front interior edge of the carcass to the trap. Standard pull-out systems require a depth of 400 mm to 450 mm. The installation height is equally critical: the system must fit beneath the trap pipework without catching when closed.

Load Capacity and Runner Technology

Wet organic waste and glass generate substantial weight. Much like a vehicle chassis, the runner carries the entire dynamic load of the unit. A simple partial-extension runner is often inadequate, as the rear bin remains difficult to access. A full-extension runner that travels 100% clear of the cabinet edge is strongly recommended. The runners should provide a load capacity of at least 30 kg to 45 kg. Sealed ball-bearing runners or concealed undermount runners also protect the running mechanism from dirt and moisture.

Overview of Types and Options

The choice of replacement system depends primarily on the construction of the sink cabinet door. The mechanism must suit the front panel.

Systems for Hinged Doors (Base Mounting)

If the cabinet is fitted with a standard hinged door opened via a concealed cup hinge with a full overlay, a base-mounted system is the appropriate choice. The waste system features its own frame that is screwed securely to the cabinet base panel. The door is opened manually, and the waste system is then pulled out via a handle. This option is exceptionally forgiving for retrofitting, as the side panels of the cabinet remain untouched.

Systems for Front Pull-Outs (Side or Front Mounting)

In modern kitchens, the front panel is often fixed directly to the waste mechanism. Pulling the handle brings out the entire pull-out kitchen bin together with the door. Here, the replacement system must include dedicated front-fixing brackets. Adjustment is carried out across three dimensions (height, side, and tilt) to achieve clean reveal gaps. The runners are typically mounted to the side panels using the System 32 hole pattern (32 mm drilling grid).

Compartment Layout (2-Way vs. 3-Way)

The number of compartments depends on the width of the cabinet and local recycling requirements.

A 2-compartment recycling bin usually provides two equally sized bins (e.g. 2 x 15 litres) for general waste and organic waste.
A 3-compartment recycling bin divides the volume further (e.g. 1 x 20 litres, 2 x 10 litres), which is ideal for separating plastic, paper, and general waste.

Which System for Which Scenario? (Selection Guide)

To ensure compatibility when replacing fittings in an Alno or Nobilia kitchen, use the cabinet width as your guide.

For a narrow 40 cm carcass: Choose a 40cm pull-out kitchen bin. These usually accommodate two bins arranged one behind the other. Base mounting is mandatory here, as the space is too restricted for side-mounted runners.
For a 45 cm or 50 cm carcass: Opt for a 45cm pull-out kitchen bin or a 50cm pull-out kitchen bin. This is the standard size for a classic 2-way system.
For a wide 60 cm carcass: This width offers maximum capacity. A 60cm pull-out kitchen bin allows bins to be positioned side-by-side. This reduces the required installation depth and prevents collisions with low-hanging waste traps.
If only the runners are defective: Often the plastic housing of the existing Nobilia system remains intact while the runners have seized. Check whether the runners can be unbolted. They can frequently be replaced with standardised undermount drawer runners of the corresponding nominal length (e.g. 400 mm or 450 mm).

Installation Guide: Replacing a Waste Separation System

Proper replacement requires precise measurement and the correct fixings.

Required Tools:

Cordless screwdriver
Folding rule and pencil
Bradawl or 3 mm wood drill bit
Wood screws (pan head or countersunk, 4 x 16 mm or 4 x 20 mm, PZ or TX drive)

Step-by-Step Installation (Base Mounting):

Removal: Remove the old unit completely. Undo all screws from the cabinet base. If you are also replacing the door hinges, remove the old concealed cup hinges / cabinet hinges.
Positioning: Place the new frame inside the empty cabinet. Maintain a setback of roughly 5 mm from the front edge of the carcass so the door can close flush.
Clearance check: Extend the runners fully to verify the full extension travel. Ensure the rearmost bin clears the sink trap freely.
Pilot drilling: Mark the frame fixing holes on the cabinet floor. Drill pilot holes using a 3 mm drill bit to a maximum depth of 5 mm to prevent tear-out in the melamine-faced chipboard.
Securing: Fasten the frame using the wood screws.
Fitting the bins: Insert the waste bins and check the smooth operation of the mechanism.

Frequently Asked Questions (FAQ)

Can I install any standard waste system into a Nobilia kitchen? Yes, provided the external cabinet width (e.g. 600 mm) and the available clear depth up to the trap match the specifications of the new system. Fixing points in the cabinet base or side panels will be drilled afresh during the upgrade regardless.

Why does my front pull-out sag downwards when opened? This is a typical sign of worn runners or overloading. When the plastic wheels of a roller runner wear down, the pull-out loses its stability. The solution is replacing the runners with heavy-duty ball-bearing slides.

What is the difference between soft-close and push-to-open on waste systems? These two mechanisms serve opposite functions. Soft-close dampens the closing motion and pulls the unit quietly into its final position. Push-to-open (tip-on) does the reverse: pressing against a handleless front releases a spring mechanism that ejects the pull-out.

How do I measure the carcass width correctly for a replacement system? Always measure the external width of the cabinet from the outside face of the left panel to the outside face of the right panel. Manufacturer ratings (e.g. "for 45 cm cabinets") always refer to this external dimension, not the internal clearance.

Can I convert a standard hinged door into a front pull-out? Yes, this is mechanically viable. Remove the concealed hinges and attach the door directly to the new waste system frame using front-fixing brackets. However, aligning the panel requires care when adjusting the reveal gaps.