Sensi Touch 2 ST76 Series Thermostat Operation Manual

The Sensi Touch 2 Smart Thermostat (models: 1F96U-42WF series, ST76 series) is a Wi-Fi enabled touchscreen 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. Requires C-wire. Below are the key specifications and operation instructions.

Key Specifications

• Type: Wi-Fi enabled touchscreen programmable smart thermostat for 24V HVAC systems
• Compatibility:
  • Single/multi-stage conventional (gas/electric), heat pumps (single/multi-stage), boilers
  • Requires C-wire for power; 2.4GHz Wi-Fi network
  • Works with Sensi app on iOS/Android; compatible with Alexa, Google Assistant, Apple HomeKit
• Power Source:
  • 24 VAC from HVAC system via C-wire (20-30VAC between RH/RC and C)
• Electrical Rating:
  • 24V systems; max 1A per terminal
  • Terminals: RH/RC, C, G, Y/Y1, Y2, W/E, W2, O/B, ACC+/ACC-, L
• 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: Compact wall-mount design with touchscreen display
• Features:
  • 7-day programming via app
  • Geofencing, energy reports, remote control
  • Touchscreen interface, back glow for installation
  • Circulating fan, humidification/dehumidification support
• Thermostat Configuration Options:
  • Models: 1F96U-42WF series, ST76 series
  • 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); screen activates.
3. Configure System:

• Select model, system type (gas/electric/heat pump) in app.
• Connect to 2.4GHz Wi-Fi via app instructions (Bluetooth-assisted via QR code or PIN).
• App guides through scheduling, location, and time zone setup.

Setting the Clock and Day

1. Syncs automatically via Wi-Fi connection.
2. Manual adjustment (Wi-Fi off): Menu > Advanced Setup > Time and Date; tap Edit and adjust.
3. Day auto-detected from app schedule and location.
4. Time zone set during app registration.

Operating in Non-Programmable Mode

1. Select Mode: Tap to cycle Off, Auto, Aux, Heat, Cool.
2. Adjust Temperature: Use Plus/Minus buttons.
3. Fan Control: Tap Fan for Auto/On; Circulate Fan via Menu (10%-100%).
4. Manual Override: Ensure Schedule Off; adjust for permanent hold ("Hold" displays).

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): Menu > Schedule; set periods.
• Enable geofencing for auto-adjust.

3. Temporary Override: Plus/Minus for 2-hour hold min.
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, geofencing, alerts, Active Savings Events (opt out via buttons).
3. Voice Control: Compatible with Alexa, Google Assistant, HomeKit.
4. HVAC Monitoring: System alerts via app.
5. Circulating Fan: Menu > Advanced Setup > Fan Mode Options; 10%-100% runtime.
6. Humidification/Dehumidification: Menu > Advanced Setup; set points (5%-50% hum, 40%-95% dehum).
7. Display Options: Menu > Display Options for time/humidity/F/C, Sleep Mode.
8. Remote Sensors: Pair via Menu; average temps.
9. Keypad Lock: Enable via app (padlock icon).
10. Temperature Limits: Set via app (45°-99°F default).

Troubleshooting

• Blank/Flashing Display: Check C-wire; ensure 20-30VAC between RH/RC and C; reset breakers.
  
• No Heat/Cool: Verify mode, wiring; check HVAC/breaker; configure in Menu > Advanced Setup.
  
• Wi-Fi Issues: Ensure 2.4GHz, update app, reboot; check permissions.
  
• Setpoint Issues: Check Schedule, automations, Geofencing, Limits.
  
• Factory Reset: Menu > About Thermostat > Reset (clears all except HVAC Equipment and Temperature Limits).

Installation Instructions

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

Remove Old Thermostat

• Switch off power to HVAC at breaker.
• Remove old cover (screwdriver or latch).
• Photograph wiring for reference.
• Discard jumper wires (Sensi has built-in).
• Identify/label wires in app; select system type.
• Disconnect wires, remove base; secure wires.

Installing New Thermostat

1. Mount Base: Level and mark holes, secure with screws/anchors.
2. Connect labeled wires to terminals (push in securely).
3. Push excess wire into wall.
4. Attach touchscreen cover to base.
5. Turn on power; screen activates.
6. Menu > Wi-Fi to initiate connection; follow app for setup, naming, location registration (QR code or PIN).

Battery Location

• No user-replaceable batteries; powered by 24V C-wire.
• Back glow switch on base for installation lighting (turn off after).

Wiring and Configuration

Match wire labels to terminals. Clip RH/RC jumper if separate transformers. Access config: Menu > Advanced Setup.

System Type	Key Connections
Conventional Single Stage (AC1/GA1/EL1)	R/RH/RC to R, C to C, G to G, Y to Y, W to W/E
Heat Pump Single Stage (HP1)	R to R, C to C, G to G, Y to Y, O/B to O/B, W to W/E
Two-Stage Conventional (AC2/GA2/EL2)	R to R, C to C, G to G, Y to Y, Y2 to Y2, W to W/E, W2 to W2
Dual Fuel Heat Pump (HP2)	R to R, C to C, Y to Y, Y2 to Y2, O/B to O/B, W to W/E, W2 to W2
Humidifier/Dehumidifier	ACC+/ACC- or Y2/W2 for accessories

Caution: Ensure secure connections. Configure system type in app or Menu during setup. C-wire required.

Terminal Definitions:

• RH/RC: Power for heating/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
• ACC+/ACC-: Accessory for humidifier/dehumidifier

Menu Configurations Reference:

Menu Item	Default	Options
Outdoor Equipment	AC2	AC1/AC2/HP1/HP2/None
Indoor Equipment	EL2	GA1/GA2/EL1/EL2/Fan
Reversing Valve	O	O/B/6/None
Humidifier	No	Yes/No; 5%-50%
Dehumidifier	No	Yes/No; 40%-95%
Circulating Fan	Off	10%-100% (5%)
Wi-Fi	-	Connect/Off
Sleep Mode	1 Min	On/Off