Rainwater systems for cisterns
Uninterrupted and standardised water supply
WISY rainwater units ensure a standardised and uninterrupted water supply - automatically controlled for the home, garden or business. A rainwater unit is like a domestic drinking water unit with an additional connection option for rainwater.
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What is a
rainwater unit?
A rainwater unit draws water from the cistern and feeds it under pressure into the rainwater pipe network so that clear process water is available at all times - completely automatically in the background.
When the toilet flushes, for example, the rainwater unit ensures that the cistern is filled as usual. At the same time, it controls the entire rainwater system, monitors the fill level in the storage tank and automatically switches to the municipal tap water supply if there is insufficient rain. This ensures a reliable supply of water from the rainwater storage tank at all times.
Function of the automatic
rainwater control
A rainwater unit pumps the water from the cistern, builds up the required line pressure for the consumers and automatically switches to the public water supply when required. As soon as a tapping point is opened, the control system recognises the pressure drop and starts the pump. If all tapping points are closed, the system detects the stopped flow and stops pump operation to save energy.
At the same time, the rainwater unit monitors the fill level in the storage tank and uses the integrated free outlet to ensure that water is replenished in accordance with standards in the event of a water shortage. In this way, the entire rainwater technology works fully automatically and continuously supplies the house and garden with service water.
Standardised drinking water make-up
What is a make-up buffer for?
For drinking water make-up, a rainwater unit always works with a buffer or make-up tank. This is the only way to realise the free outlet required by standards, which ensures a safe separation between the drinking water installation and the rainwater system. The tap water is not fed directly into the supply network, but is first stored temporarily.
This make-up buffer is designed differently depending on the system: In the Sigma, Optima and Optima Plus rainwater systems, the buffer tank is located in the wall-mounted unit inside the building. In the high-performance Maxima system, a large buffer tank in the floor-mounted unit takes over this function. With the Multimat, the t is utilised so that the cistern is replenished in a standardised and reliable manner. In all cases, the make-up buffer ensures that the supply is standardised, hygienic and reliable.
Which rainwater unit
suits my needs?
Even if every rainwater system is essentially based on the same components, there are individual requirements. WISY offers a customised rainwater unit for every situation - whether single-family homes or apartment blocks, commercial or industrial buildings, sports facilities or public institutions.
Selection
the right rainwater unit
The selection of the right system depends, among other things, on the required system pressure, the desired flow rate and the distance and height difference between the cistern, wall-mounted unit and the extraction points.
WISY offers rainwater units that pump the water directly from the cistern using a submersible pressure pump (Multimat) or in which a self-priming pump is installed in the wall-mounted unit (Sigma). A combination of both principles is also available, for example for large distances and height differences between the cistern and the building (Optima and OptimaPlus). If a particularly high supply capacity is required, the Maxima rainwater unit is used, which can supply several households and is also used in industry and commerce.
Orientation according to
Building type and requirements
Classic detached house
Recommendation: SIGMA
Ideal for short distances between the cistern and the plant room. The pump installed in the house makes installation and maintenance easier.
House without basement
Recommendation: MULTIMAT
Compact wall-mounted device with minimum space requirement in the building. The powerful cistern pump ensures particularly quiet operation in the house.
More comfort & stable pressure
Recommendation: OPTIMA
Two-pump system for constant pressure conditions with multiple tapping points. Conveniently suitable for one to two residential units.
Increased safety & greater distance
Recommendation: OptimaPLUS
Self-sufficient pumps increase reliability. Suitable for greater distances between the cistern and the building.
Apartment block or business
Recommendation: MAXIMA
Large buffer cylinder with its own control unit. Designed for up to eight residential units or commercial applications.
Areas of application
Comparison of rainwater units
Sigma
Accessible pump
To the product
The Sigma is suitable for detached houses where only small differences in height or short distances between the cistern and the wall-mounted unit need to be bridged. The pump installed in the house makes the system easily accessible for installation and maintenance.
Multimat
Compact and quiet operation
To the product
The Multimat rainwater unit is designed for detached houses without basements. The compact wall-mounted unit takes up very little space in the house, while the powerful cistern pump ensures very quiet operation. The water is pumped entirely from the cistern.
Optima
Comfort and pressure
To the product
The Optima is suitable for households with increased comfort requirements. Thanks to its dual-pump system, the combination of a cistern pump and simultaneously operating pressure pump in the wall-mounted unit ensures particularly stable pressure conditions.
OptimaPLUS
Redundant security
To the product
The OptimaPLUS rainwater unit is designed for applications with special safety requirements. The independently operating pumps ensure increased reliability. At the same time, it is suitable for longer distances.
Maxima
Commercial or large units
To the product
The Maxima is designed for apartment blocks with up to eight residential units and for commercial applications. A large buffer cylinder with its own control unit enables high flow rates and a stable supply even with fluctuating demand.
System differences
at a glance
| SIGMA |
MULTIMAT | OPTIMA | OPTIMA-PLUS | MAXIMA |
|---|---|---|---|---|
| Easy installation and maintenance | Compact wall-mounted unit, quiet operation thanks to cistern pump | Stable pressure conditions | Increased reliability | Freestanding unit for larger units |
| Area of application | ||||
| Detached house | Detached house without basement | Comfort for 1-2 families | Long distance | 2-8 households and businesses |
| Distance to the cistern | ||||
| up to 12 m | up to 20 m | up to 20 m | up to 50 m | up to 20 m (further on request) |
| Active pumps in rainwater operation | ||||
| Self-priming centrifugal pump in wall-mounted unit | Pressure pump in the cistern | Charging pump in the cistern and pressure pump in the wall-mounted unit | Self-sufficient pressure pump in the cistern | Charging pump in the cistern and separately controlled pressure pump in the free-standing unit |
| Active pumps in make-up operation | ||||
| Self-priming centrifugal pump in the wall-mounted unit | Pressure pump in the cistern | Centrifugal pump in the wall-mounted unit | Centrifugal pump in the wall-mounted unit | Pressure pump in the floor unit |
| Make-up via | ||||
| 9 litre buffer tank | Cistern as buffer tank | 9 litre buffer tank | 9 litre buffer tank | 350 litre buffer tank |
| Power consumption in standby mode | ||||
| < 0.2 watts | < 0.2 watts | < 0.2 watts | < 0.2 watts | < 0.2 watts |
All rainwater units
Individual in detail
Rainwater from
the cistern...
SIGMA in rainwater mode:
The rainwater is sucked into the cistern and then conveyed to the consumers.
SIGMA is a rainwater unit in which a centralised suction and pressure pump is installed in the wall unit inside the building. The pump draws the rainwater from the cistern and pumps it under pressure directly to the connected consumers. This makes the system suitable for installations in basements, for example, where an easily accessible and clear installation in the house is desired.
If the water level in the cistern falls below the required level, the rainwater unit automatically switches to make-up mode. For this purpose, the Sigma rainwater unit has an integrated 9-litre buffer tank that is permanently filled with tap water. If the rainwater is no longer sufficient, the same pump takes over the delivery of drinking water directly from this storage tank to the consumers. In this way, it works as a domestic waterworks with drinking water replenishment and ensures a continuous water supply.
...or make-up water
with public tap water
SIGMA in make-up operation:
The tap water is pumped from the buffer tank in the wall-mounted appliance to the consumers.
Rainwater from
the cistern...
MULTIMAT in rainwater mode:
The rainwater is pumped directly from the cistern to the consumers.
The water is replenished via a free outlet installed in the house within the wall-mounted unit, which feeds public tap water into the cistern as required. If the water level in the storage tank falls below a defined minimum, a float switch activates the automatic replenishment of the cistern. The daily requirement of a detached house is supplemented with mains water to ensure the supply until the next rain event.
Regardless of whether rainwater or mains water is used, the water is always pumped to the consumers via the Multimat cistern pump. The water only flows through the wall-mounted device in the house to control the integrated automatic switch. This means that the Multimat works as a rainwater domestic water system with constant pressure and consistent operation.
...or make-up water
with public tap water
MULTIMAT in make-up operation:
The mains water is channelled from the rainwater works to the cistern and pumped from there to the consumers.
for rainwater from
from the cistern...
OPTIMA in rainwater mode: The feed pump transports the rainwater from the cistern to the wall-mounted unit, from where it is pumped to the consumers with additional pressure.
The Optima rainwater unit operates in rainwater mode with two pressure pumps simultaneously, ensuring particularly stable pressure conditions in the supply network. A feed pump in the cistern transports the water from the storage tank to the wall-mounted unit in the house and acts as an upstream charging pump. This can even compensate for any faults caused by air pockets in the intake.
A second pressure pump is integrated into the wall-mounted unit, which pumps the water provided - either rainwater from the cistern or, if required, municipal tap water - to the consumers at a constant pressure. Due to this division of the pumping tasks and the redundancy of the pumps, the Optima is particularly stable as a rainwater domestic water unit and is suitable for applications with increased requirements for convenience and pressure consistency.
...or for topping up
with public tap water
OPTIMA in make-up operation:
The tap water is pumped from the buffer tank in the wall-mounted appliance to the consumers.
For rainwater from
from the cistern...
OptimaPLUS in rainwater mode:
The rainwater is pumped directly from the cistern to the consumers.
The OptimaPLUS rainwater unit also has two pumps, but only one of them works at any one time. In rainwater mode, only the particularly powerful cistern pump pumps the rainwater directly to the consumers. In this operating mode, the water only flows through the wall-mounted unit to control the integrated automatic switch.
In automatic make-up mode, the pressure pump installed in the wall-mounted device supplies the consumers. It pumps the tap water from the integrated 9-litre buffer tank directly into the domestic supply network. The two pumps in the cistern and wall-mounted unit therefore work independently of each other. The OptimaPLUS rainwater unit works fully automatically, but can also be switched manually between rainwater operation and drinking water replenishment if required. It is suitable for longer distances of up to 50 metres.
...or for topping up
with public tap water
OptimaPLUS in make-up operation:
The tap water is pumped from the buffer cylinder in the wall-mounted appliance to the consumers.
For rainwater from
from the cistern...
MAXIMA in rainwater mode:
The rainwater is pumped from the cistern to the large buffer tank. Controlled separately, it is transported from there to the consumers.
The Maxima rainwater unit is characterised by its large buffer tank with independent, precise control. Depending on the fill level in the cistern and buffer tank, the two pumps - the charging pump in the cistern and the powerful submersible pump in the buffer tank - are activated independently of each other. This allows the water supply to adapt flexibly to changing operating conditions.
In rainwater mode, the buffer cylinder is filled with rainwater by the charging pump in the cistern. If the water supply in the tank is insufficient, the buffer tank is automatically topped up with tap water from the public supply network. In both operating modes, the consumers are supplied exclusively from the buffer cylinder. The powerful feed pump ensures a constant system pressure so that the Maxima can also reliably supply larger buildings, commercial systems or up to eight households. This makes the system particularly suitable for applications with high power requirements for a centralised rainwater system.
...or for topping up
with public tap water
MAXIMA in make-up operation:
The water is pumped from the buffer tank to the consumers.
Advantages of the WISY rainwater units
Sophisticated system technology for a reliable water supply
WISY rainwater units are designed as fully integrated supply systems and perform all the central functions of rainwater utilisation in a single device. They ensure a reliable water supply, regardless of whether there is sufficient rainwater in the cistern or whether tap water has to be used.
Automatic switching between rainwater and drinking water operation ensures an uninterrupted supply to the connected consumers. The control system works according to demand and only starts the pumps when water is actually being drawn. This reduces energy consumption and protects the system technology.
Another advantage is the standardised design of the drinking water make-up. All systems work with a free outlet and a make-up buffer, which ensures reliable separation between the public drinking water network and the rainwater system. Depending on the model, the make-up water is fed via the wall-mounted unit, a separate buffer tank or directly via the cistern.
Thanks to different pump concepts, the rainwater units can be precisely adapted to the respective application - from compact systems for single-family homes to high-performance solutions for apartment blocks, commercial and industrial applications. The modular systems enable stable pressure conditions, quiet operation and high operational reliability over many years.
Energy efficient
through ZETA 02
All WISY rainwater units ensure automatic and demand-orientated replenishment with mains water, so that an uninterrupted water supply is always guaranteed without your intervention. All make-up devices comply with standards and therefore fully fulfil the requirements of the Drinking Water Ordinance.
Thanks to the ZETA 02 automatic switch integrated into all devices, the rainwater units also only require 0.2 watts in standby mode, which is up to 97 % more economical than conventional systems. This allows you to conserve the valuable resource of water and is also energy efficient.
Installation and requirements
Basics for safe and reliable operation
A number of basic installation requirements must be met for the reliable operation of a rainwater unit. These include, in particular, the positioning of the components, the pipework between the cistern and the building and the integration into the building's internal supply network.
Depending on the system, the installation is carried out as a wall-mounted appliance in the building or as a free-standing appliance. Wall-mounted appliances such as Multimat, Sigma, Optima and Optima Plus are usually installed in the basement or in a utility room. Care should be taken to ensure an easily accessible position so that maintenance and service work can be carried out easily. The Maxima system is installed as a free-standing appliance and requires a correspondingly larger footprint, but offers a large buffer tank for higher supply capacities.
The connection between the cistern and the rainwater unit is made via a suction line or delivery line in a technical pipe, depending on the respective pump concept. Both the distance and the height difference between the cistern and the building play an important role in the design of the system. The drinking water replenishment is always realised in accordance with standards via a free outlet, either in the wall-mounted unit, in the free-standing unit or - in the case of the Multimat - via the cistern itself.
Professional installation of the electrical connections as well as the control and safety devices is also required for safe operation.
All rainwater units
from WISY
Suitable accessories
for our rainwater units
Find the right rainwater unit
Customised design for your project
Whether it's a detached house, apartment block or commercial use - we can help you with the technical design and selection of the right system.