Sensi Smart Thermostat Operation Manual

The Sensi Smart Thermostat (model 1F87U-42WF) is a Wi-Fi enabled programmable thermostat designed for 24V HVAC systems in the US and Canada. It provides smart control via the Sensi app, offering scheduling, remote access, and energy savings. Compatible with single/multi-stage conventional systems, heat pumps, and more. Below are the key specifications and operation instructions.

Key Specifications

• Type: Wi-Fi enabled programmable smart thermostat for 24V HVAC systems
• Compatibility:
  • Single/multi-stage conventional (gas/electric), heat pumps, boilers
  • Requires C-wire for most systems; adapter available for no C-wire
  • Works with Sensi app on iOS/Android; compatible with Alexa, Google Assistant, Apple HomeKit
• Power Source:
  • 24 VAC from HVAC system
  • Backup: 2 AA alkaline batteries
• Electrical Rating:
  • 24V systems; max 1A per terminal
  • Terminals: RH/RC, C, G, Y/Y1, Y2, W/W1, W2, O/B, L, AUX
• Temperature Range: 45°F to 99°F (7°C to 37°C); Humidity: 5% to 90% RH non-condensing
• Operating Conditions:
  • Indoor use only; 40°F to 120°F (4°C to 49°C)
  • Wi-Fi: 2.4GHz network required
• Dimensions: 3.75" H x 4.75" W x 1.25" D; wall-mount design
• Features:
  • 7-day programming via app
  • Geofencing, energy reports, remote control
  • Optional remote sensors
  • Backlit display, intuitive controls
• Thermostat Configuration Options:
  • Models: ST55, 1F87U-42WF
  • UL listed; professional or DIY installation

Operation Instructions

Initial Setup

1. Download Sensi App: Install from App Store or Google Play; create account with email.
2. Power On: Install on wall after wiring (see Section 3); pull battery tab.
3. Configure System:

• Select model, system type (gas/electric/heat pump) in app.
• Connect to 2.4GHz Wi-Fi using Sensi security code.
• App guides through scheduling and location setup.

Setting the Clock and Day

1. Syncs automatically via Wi-Fi connection.
2. Manual adjustment (Wi-Fi off): Hold Schedule button until time flashes; use arrows to set.
3. Day auto-detected from app schedule and location.
4. Time zone set during app registration.

Operating in Non-Programmable Mode

1. Select Mode: Press Mode to cycle Heat, Cool, Off, Aux.
2. Adjust Temperature: Use up/down arrows.
3. Fan Control: Press Fan for Auto/On; set circulating fan % via Menu.
4. Manual Override: Turn Schedule Off for permanent hold; arrows for temp.

Operating in Programmable Mode

1. Factory Schedule: Default 7-day program via app.
2. Custom Schedule:

• Use Sensi app: Schedule tab to set times/temps.
• Manual (Wi-Fi off): Hold Schedule, set 4 periods per day.
• Enable geofencing for auto-adjust.

3. Temporary Override: Arrows for 2-hour hold.
4. Permanent Hold: Turn Schedule Off.
5. Disable Programming: Schedule Off in app or on unit.

Advanced Features

1. Remote Control: Via Sensi app with Wi-Fi.
2. Energy Saving: Usage reports, alerts, geofencing.
3. Voice Control: Compatible with Alexa, Google Assistant, HomeKit.
4. HVAC Monitoring: System alerts via app.
5. Sensors: Optional Sensi remote temperature sensors.

Troubleshooting

• No Display: Check power, batteries; replace AA if low.
  
• No Heat/Cool: Verify mode, wiring; check HVAC fuses.
  
• Wi-Fi Issues: Ensure 2.4GHz, restart app/router; use another device.

Installation Instructions

Warning: Turn off power at breaker before starting. DIY or professional installation. Requires C-wire for full functionality.

Remove Old Thermostat

• Switch off power to HVAC at breaker.
• Remove old cover, take photo of wiring.
• Label wires with provided stickers, disconnect.
• Remove base from wall; secure wires.

Installing New Thermostat

1. Mount Base: Level and mark holes, drill/anchor, screw base to wall.
2. Connect labeled wires to terminals.
3. Push excess wire into wall.
4. Insert batteries, pull tab, snap display onto base.
5. Restore power; follow app for Wi-Fi setup.

Battery Location

• 2 AA alkaline batteries in compartment on back of display.
• Provides backup power; replace when low battery icon shows.

Wiring and Configuration

Match wire labels to terminals. Clip RC/RH jumper if separate transformers.

System Type	Key Connections
Conventional Single Stage	R/RH to R, C to C, G to G, Y to Y, W to W
Heat Pump Single Stage	R to R, C to C, G to G, Y to Y, O/B to O/B
Two-Stage Conventional	R to R, C to C, G to G, Y1 to Y, Y2 to Y2, W1 to W, W2 to W2
Dual Fuel Heat Pump	R to R, C to C, Y1 to Y, O/B to O/B, W to AUX
Humidifier/Dehumidifier	AUX to Y2 or dedicated

Caution: Ensure secure connections. Configure system type in app during setup.