The Programmable Thermostat 521 is designed for three different modes of operation: single stage heating, two stages of heating with a fan, or one stage of heating and one stage of cooling with a fan. Two auxiliary sensors may be added to measure the floor, outdoor or room temperature. A Slab Sensor 079 is included to measure floor temperature to protect the floor from overheating and enhance comfort. The programmable schedule supports either a 7 day or 24 hour schedule with 2 or 4 events per day. A permanent temperature hold button overrides the programmable schedule. An optional Adaptor Plate 012 is available to allow the thermostat to mount onto a single gang electrical box.

Features

• Fan

• Outdoor and floor temperature display

• Backlight

• Cooling

• Time clock

• Four hour battery-free clock backup

• Two stage heating

• Permanent temperature hold, radiant floor heating

• 7 Day programmable schedule, optimum start