- Class-leading low energy consumption (as low as £3 per house per year)
- Easy to install
- No mains back up to main storage tank
- WRAS Approved
- Simple maintenance
- Quiet operation
- Highly suited to retro-fit systems
The WISY® Sigma rainwater unit is extremely versatile and is suitable for most domestic installations, both for new properties and also to retro-fit into an existing one. It can be used with underground or above ground tanks and is very simple to install.
Mains water back up is achieved via a small break tank built into the Sigma unit. This mini break tank accepts the mains water supply and provides the required statutory air gap to prevent the cross contamination of mains water supply. As of April 2016, all Sigma units are WRAS Approved.
Having the mains water supply go to the pumping unit rather than to the main storage tank has certain advantages, and saves on having to provide ‘top-up’ to the main tank.The system can be switched to run from the mains supply only should you wish and is extremely quiet in operation.
The Sigma unit is built from the best possible components and with the quality engineering that is typical of WISY® AG.
Combined with one of our RainSava GRP tanks, ranging in size from 1,000 litres upwards, we offer a simple solution for most domestic properties. And being WRAS Approved means installers and householders have peace of mind.