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Pro1 - T855i 5/1/1 Programmable or 7 Day or Non-Programmable Wi-Fi Thermostat, 4H/2C with 8 sq. in. Display

Item: T855i
MFR: T855I

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About This Product

Product Info


The New T855i Wi-Fi Thermostat is sold exclusively to HVAC professionals. Here are some of the features that make the T855i the best value in the Wi-Fi market:
  • Easy Setup - If you know how to install any Pro1 thermostat you know how to install a Wi-Fi model. The quickstart guide will walk the homeowner through the WI-FI linking procedure.
  • Universal Subbase - Fast, easy upgrade from existing Pro1 thermostats. No additional wiring necessary as long as C is connected.
  • Private Label - Contractor contact info displayed in mobile app and on magnetic badge of thermostat to generate return business.
  • Smart Grid Capable - Works with many utility incentive programs. Learn more from your professional installer or Pro1 representative.
  • Control From Anywhere - Monitor and control your HVAC system anywhere using your computer, smart phone or tablet.
  • Active Alerts - Receive customized alerts from anywhere. High and low temp. limits, connection status, and more.


  • 7 Day or 5/1/1 programmable
  • Auto Changeover
  • Easy menu driven programming
  • Intuitive wake, leave, return, sleep programming icons
  • 8 square inch display
  • Blue backlight
  • Glow in the dark light button
  • Programmable fan
  • Electric or Gas configurable
  • Room temperature calibration adjustment
  • Separate heating and cooling swing (cycle rate) adjustments
  • Keypad lockout
  • Heating and cooling set point limits
  • 5 minute compressor delay protection (selectable on or off)
  • Filter change indicator(selectable on or off)
  • Simple private label badge system
  • Easy wire color coded terminal blocks
  • Universal sub-base
  • Mounts on wall or junction box
  • 24V power
  • 3 year warranty


Weight0.8 Pounds (lbs)
Width4.7 Inches (In)
Height4.6 Inches (In)
Country of OriginCHN
Length1 Inches (In)
750mV CompatibleYes
Accuracy1º F
Ambient Temperature Range32°F to 105°F (0°C to 40.5°C)
ApplicationCommercial and Residental
Auto ChangeoverYes
Batteries IncludedNo
Battery BackupNo
Built In Wi-FiYes
Change/Check RemindersYes
Daylight Savings Time ReadyYes
Differential TemperaturePlus or minus 2 degree
Digital-Non ProgrammableYes
Display OptionsLCD, Backlit
Displays Outdoor TemperatureNo
Dual Transformer CompatibleYes
Electrical Connection18 to 30 VAC, NEC Class II, 50/60 HZ for Hardwire
Electrical Rating18-30 VAC, NEC Class II
Energy Star RatedNo
Fan SwitchingYes
Heat Pump CompatibleYes
Indoor Remote SensorNo
Low Battery IndicatorYes
MountingDrywall, stud, junction box
Number of HVAC Zones1
Operating Temperature Range31°F to 105°F (-0.5°C to 40.5°C)
Power MethodHardwired
Programmable FanYes
Prop 65No
Removable InterfaceNo
Sensing ElementYes
Stages Cool2
Stages Heat3
Switch ActionRelay
System SwitchingYes
Temperature Range44°F to 90°F (6.6°C to 32.2°C)
Temperature Settings per Day4
Terminal DesignationsRh, Rc, C, Y, Y2, W/E, W2 G, O, B
Vacation ModeYes
Voltage24 VAC
Warranty OfferedYes


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