

- Class-leading low energy consumption (as low as £3 per house per year)
- Easy to install
- No mains back up to main storage tank
- Pending WRAS re-approval
- Simple maintenance
- Quiet operation
- Highly suited to retro-fit systems
- Perfect for drawing water from an above ground tank

The WISY® Sigma rainwater harvesting management 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 is also ideal for use with above ground tanks, as the pump is located within the house so is not vulnerable to frost.
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, particularly where used with an above ground storage 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.
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