The DEVIreg™ 850 is an advanced thermostat with LED display used for outdoor ground or roof applications.

The sensors provide information about both moisture level and temperature, resulting in an optimal control of the heating system.

The system can be set up in three ways; as a single system for roof or ground (1 to 4 sensors), as a dual system for roof or ground (2 - 4 sensors) or as a combination system for roof and ground (2 - 4 sensors).
In the dual / combination systems it is possible to prioritize between the zones, e.g. if only a limited power output is available.

Features and benefits

Single, combination or dual zones

Up to 4 sensors

Moisture and temperature sensing

Self diagnosing program

Safety level adjustment

Alarm function

DEVIreg™ 850

DEVI application for roof and gutters with thermostat DEVIreg™ 850

DEVI ice and snow melting system for roofs consists of heating cables, an electronic thermostat, and installation accessories. DEVI ice and snow melting solutions for roofs can be installed in any type of roof construction.


Type Name Language Valid for Updated Download File type
Operating guide Danfoss EFIT™ 850 Controller instruction English Multiple 02 May, 2019 1.5 MB .pdf
Operating guide DEVIreg 850 English Multiple 02 May, 2019 1.6 MB .pdf
Operating guide Devireg 850 Sensor English Multiple 02 May, 2019 422.3 KB .pdf
Data sheet EFIT™ 850 ice and snow melting English Multiple 02 May, 2019 537.4 KB .pdf
Operating guide EFIT™ 850 Sensor instruction English Multiple 02 May, 2019 774.1 KB .pdf
Brochure Experience life's hidden comforts - at a touch English United Kingdom 14 Jul, 2019 1.1 MB .pdf


DEVIwarranty™ – your peace of mind

At DEVI, we find it of great importance to deliver high quality products with long lasting effects. We offer you the best warranties in the market.

DEVIwarranty™ is a series of 4 individual, best-in-market warranties to give you full peace of mind while using DEVI products in electric heating systems.

Read more about DEVI warranty™

To register for the DEVIwarranty™ please go to your local Danfoss website and find the online registration form.
Register for DEVI warranty™

Case studies

  • Ice and snow melting in the City of Buffalo, USA

    According to the National Weather Service, a series of lake effect events and clipper-type systems dumped 112 inches of snow on Buffalo, New York, in the winter of 2014-15. In an area accustomed to harsh winters, this was still unusual – about 18 inches above normal. But even this impressive amount of snow was no match for the Danfoss snow melt system installed at Canalside.

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These application manuals present DEVI’s recommendations for design and installation of heating systems for both indoor and outdoor applications

See application manuals