Sensi 1F87U-42WF Thermostat Operation Manual

The Sensi 1F87U-42WF Smart Thermostat is a Wi-Fi enabled programmable thermostat for 24V HVAC systems. It offers smart control via the Sensi app, including 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: 1F87U-42WF, ST55
  • 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.
6. Keypad Lock: Enable in app (padlock icon).
7. Display: Backlight (10s), time/humidity/F/C toggle in Menu.

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.
  
• Heat Only in Aux: Set Indoor Equipment to Gas/Electric (not Heat Pump) in Menu.
  
• Fan Percentage: Sets hourly run time (e.g., 50% = 30 min/hr, minus HVAC cycles).

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.
• Discard jumper wires; Sensi has built-in jumper.
• Identify wires in app; select system type (gas/electric/heat pump).

Installing New Thermostat

1. Install 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.
6. Initiate setup: Press Menu > Mode; Wi-Fi icon flashes.
7. Follow app for Wi-Fi connection, name thermostat, register location.

Battery Location

• 2 AA alkaline batteries in compartment on back of display.
• Provides backup power; replace when low battery icon shows (3 bars).

Wiring and Configuration

Match wire labels to terminals. Clip RC/RH jumper if separate transformers. Access configuration: Press Menu on thermostat.

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. Common wire (C, B, or X) required.

Terminal Definitions:

• RH: Power for heating, 24V
• RC: Power for cooling, 24V
• C: Common wire, 24V
• G: Indoor blower (fan)
• Y: First stage cooling/heat pump
• Y2: Second stage cooling or humidifier
• W/E: First stage heat or aux/emergency
• W2: Second stage heat or dehumidifier
• O/B: Reversing valve for heat pump
• L: Heat pump system monitor

Menu Configurations Reference:

Display Code	Menu Item	Default	Options
—	Wireless Setup	—	Connect to Wi-Fi
F	Fahrenheit or Celsius	F	F / C
—	Outdoor Equipment Config	—	AC1/AC2/HP1/HP2/AC0
—	Indoor Equipment Config	EL2	EL1/EL2/GA1/GA2/FAn
—	Reversing Valve Position	O	O / B (Heat Pumps)
2 Fn	Circulating Fan	OFF	OFF/10%-100% (5%)
H AA	Humidification Accessory	OFF	OFF/ON
H SP	Humidification Set Point	OFF	OFF/5%-50% (5%)
dH AA	Dehumidification Accessory	Od	Od/Oc
dH SP	Dehumidification Set Point	OFF	OFF/40%-95% (5%)
—	Wireless Radio	ON	OFF/ON

Back of Thermostat: Security code for Wi-Fi, model, HomeKit code, RC/RH jumper (clip if separate), battery compartment, date code, MAC ID.