Rainwater units for an uninterrupted water supply

What are rainwater units used for?

WISY rainwater units ensure that clear service water is always available for use - and they do this completely automatically in the background, without you noticing.

A rainwater unit withdraws water from the cistern and feeds it under pressure into the rainwater pipe network. When the toilet is flushed, for example, the rainwater unit ensures that the cistern is filled up as usual.

In doing so, it controls the entire rainwater system. It checks the fill level in the cistern and automatically switches over to the use of municipal tap water if there is too little rain. This ensures that consumers are supplied with water at all times.

Precisely tailored to your individual application

Even though every rainwater system relies on the same components at its core, yours will have some individual specific requirements. WISY offers you a custom-fit solution for every situation - whether single-family or multi-family homes, commercial or industrial buildings, sports facilities or public facilities.
The right rainwater unit is selected according to the required system pressure, the desired flow rate and the distance and height difference from the cistern to the wall-mounted unit.
WISY offers rainwater units that pump the rainwater directly from the cistern using a submersible pressure pump (Multimat) or with a self-priming pump built into the wall-mounted unit (Sigma). A combination of both for long distances and height differences is also available (Optima and Optima Plus). If a particularly high supply capacity is required, the Maxima rainwater unit is used. Depending on the variant, it can supply up to eight households and is also used in industry and commerce.

Standard-compliant and energy-efficient

All WISY rainwater harvesting units ensure automatic and on-demand top up with tap water, so that an uninterrupted water supply is always guaranteed without your intervention. All top up devices are standard-compliant and therefore fully meet the requirements of codes and standards.

Thanks to the ZETA 02 pump controller which is integrated in all units, they only use 0.2 watts in standby mode, making them 97 % more economical during standby than conventional systems. 

Overview of WISY rainwater units

Product information

Multimat rainwater unit

The Multimat rainwater unit uses a submersible pump to pump rainwater out of the storage tank and feeds it under pressure into the rainwater pipe network. It controls the system, checks the fill level of the storage tank and, if necessary, automatically ensures that mains water is fed into the rainwater storage tank.

The Multimat rainwater unit works with two separate cables from the cistern to the wall-mounted unit. This ensures simple installation and long-term operational reliability. Two sockets must be provided on site.

To the product

InfoImportant details

Compact and quiet, no pump inside the house One day demand water top up into the cistern during dry times Only 0.2 watts standby consumption Submersible pump in the cistern Max. Delivery rate 125 l/min max. pressure head 49.4 m For longer delivery distances or greater height differences

Product information

Sigma rainwater unit

The fully automatic Sigma rainwater unit supplies a single-family house with rainwater.

It takes rainwater from the cistern and feeds it under pressure into the rainwater pipe network. The unit controls the entire rainwater system, checks the fill level of the storage tank and automatically switches over to the use of mains water if necessary.

To the product

InfoImportant details

Compact and economical Automatic switching between rainwater and mains water Only 0.2 Watt standby consumption Suction pump in wall unit Max. Delivery rate 66 l, max. pressure head 44 m Ideally suited for single-family houses

Product information

Optima rainwater unit

The rainwater unit combines all the components required for operation in one unit, pumps the water from the rainwater storage tank and feeds it under pressure into the rainwater pipe network.

The rainwater unit controls the entire rainwater system, checks the fill level of the storage tank and, if necessary, automatically switches over to mains water within the wall-mounted unit.

To the product

InfoImportant details

Compact and economical Automatic switching between rainwater and mains water Only 0.2 Watt standby consumption Two pumps for stable pressure conditions: Feeder pump in the cistern and pressure pump in the wall-mounted unit Max. Flow rate: 70 l/min; up to 5 bar system pressure Convenient solution for detached and semi-detached houses

Product information

Optima Plus rainwater unit

The OPTIMA PLUS rainwater unit combines all the components required for operation in a single unit. It pumps the rainwater from the rainwater storage tank over long distances and large delivery heads and feeds it into the rainwater pipe network.

It controls the entire rainwater system, checks the fill level of the storage tank and, if necessary, automatically ensures mains water top up within the wall-mounted unit.

To the product

InfoImportant details

For up to 50 m distance or big height differences from cistern to wall unit Top up of mains water within the 9 Liter tank in the wall-mounted unit Only 0.2 watts standby consumption Double fail-safe: Separate pumps for rainwater or mains water operation Max. Flow rate 70 l/min, up to 4.7 bar system pressure

Product information

Maxima rainwater unit

The Maxima rainwater unit ensures a high supply capacity thanks to the large hybrid tank. It combines all components required for the operation of the rainwater supply system according to the two-pressure pump principle.

The rainwater is pumped from the rainwater storage tank into the buffer tank of the hybrid system by the submersible feeder pump in the tank. From the buffer tank the submersible pressure pump supplies the points of use. Mains water is replenished directly into the buffer tank when the rainwater tank is empty. The buffer volume is 350 l for high demand peaks.

To the product

InfoImportant details

High supply and operating safety due to 350 l buffer volume Top up with mains water inside the buffer tank Only 0.2 Watt standby consumption Two submersible pressure pumps: in the Rainwater tank and in the buffer tank Max. Delivery rate 120 l max. pressure head 49 meter Plug-in system, requires no electrical work

Suitable connection sets for rainwater units

Other accessories

water sensor water sensor
water sensor
US$46.20*
Wall-mounting bracket AspriPlus pump