Micro 4 L Compact Water Softener with Runxin F79B Valve

The Micro 4 L Compact Water Softener is an ultra-compact, automatic water softening system designed for installations where space is limited and water demand is relatively low. Featuring a Runxin F79B LCD metered control valve, 4 litres of softening resin and a neat white cabinet, this small water softener offers effective protection against limescale in domestic and light commercial applications.

Ideal for dishwashers, glasswashers, individual appliances, small flats and low-demand water supplies, the Micro softener helps reduce hardness-related scale deposits, protecting heating elements, pipework and connected equipment.

Its compact design makes it particularly suitable for installations in pubs, restaurants, cafés and domestic properties where a full-sized water softener may not be practical.

Key Features and Benefits

• Ultra-compact design: Measuring just 255 mm wide × 440 mm high × 430 mm deep, suitable for restricted installation spaces.

• Automatic metered regeneration: The Runxin F79B LCD valve monitors water consumption and manages regeneration according to usage.

• 4 litres of softening resin: Provides a nominal treatment capacity of 667 litres at 300 ppm hardness as CaCO₃.

• Low salt consumption: Uses approximately 0.5 kg of tablet salt per regeneration.

• Digital LCD display: Shows operating status, remaining water capacity and regeneration information.

• Pre-programmed controller: Supplied with model-specific settings. Only the clock and local water hardness or capacity normally require adjustment during commissioning.

• Standard ¾" BSP connections: Female threaded inlet and outlet connections for plumbing integration.

• Automatic regeneration schedule: Factory regeneration time is 02:00, with a maximum regeneration interval of seven days.

Suitable Applications

The Micro 4 L water softener is particularly well suited to:

• Commercial glasswashers and dishwashers in pubs, cafés and restaurants.

• Individual domestic dishwashers and washing machines.

• Small flats and single-occupancy properties with low water demand.

• Selected appliances requiring softened water to reduce limescale formation.

Important: The softener should be selected according to the appliance's instantaneous fill rate, daily water consumption and incoming water hardness.

Technical Specifications

The optimum softening flow is based on the GAPS sizing guideline of 40 litres/hour per litre of resin and should not be confused with the maximum hydraulic flow capacity of the valve.

Water Softening Capacity

The Micro softener's treatment capacity depends on the incoming water hardness. At a hardness of 300 ppm as CaCO₃, the nominal capacity is approximately 667 litres between regenerations.

For comparison:

These values are calculated capacities before any separately specified reserve allowance. Actual performance depends on operating conditions and controller settings.

Installation and Regeneration

The Micro softener is supplied pre-programmed for its resin capacity. During installation, the incoming water hardness should be measured and the controller adjusted accordingly.

A suitable water supply, bypass arrangement, regeneration drain, separate gravity overflow and electrical connection are required.

Please note: The Runxin F79B supplies untreated water during regeneration. Regeneration should therefore be scheduled during periods of low water demand, particularly when supplying equipment that requires softened water continuously.

For full installation, commissioning, programming and maintenance instructions, refer to the GAPS Runxin F79B Installer Manual 2026.