The program is only valid in UK. Vouchers are only valid for orders shipped to the UK.

How it works

Follow these simple steps:

1. Send the invitation to your friends

2. Your friends receive 20% off, redeemable in our online shop

3. You will receive 20% off after their first purchase

Voucher codes are valid until 31.12.2022 and can only be redeemed at

Referral discounts may vary and cannot be combined with other promotions or vouchers. Refurbished devices are excluded from the referral programme. 

*Based on the Fraunhofer Institute for Building Physics IBP from the "Simulation Study on Energy Saving Potential of a Heating Control with Absence Detection and Weather Forecast", IBP Report 527 (2013).