Video at Amazon.com View HR-20 Honeywell has long been a classic among the electronic thermostats for radiators. In addition to the HR-20, there was the HR-40 as expensive brother, which, however, the same technology, and only one case had wertigeres than the old HR-20. The housing of the old HR 20 was held a little cheap. The newer HR20 style contained the same sophisticated technology as the first HR-20 and HR-40, even the same software version. However, the HR20-style offered a stylish casing which is moreover processed very valuable.
The new HR 25 Energy now has three temperature phases instead of two as the three older models. A Ecotaste lowers temperatures chosen again from around 3 ° C. The display has been enlarged and now shows much more information. The two AA batteries not included.
Overall, the HR-25 is the best electronic radiator valve that I know.
For device itself just look at the video I've taken)