Sensi · Standalone

Sensi 1F87U-42WF Smart Thermostat

Wi-Fi thermostat with app scheduling for conventional systems up to 2H/2C and heat-pump systems up to 4H/2C, subject to wiring and common-wire requirements.

Legacy model

Sensi 1F87U-42WF

Sensi 1F87U-42WF

Will this work with my system?

Match your equipment to these requirements before ordering.

Works with

  • Conventional gas, oil or electric systems up to 2H/2C
  • Heat pumps up to two compressor stages with auxiliary heat, maximum 4H/2C
  • Documented three-wire zone-valve applications with a common wire

System requirements

  • 20–30 VAC control system.
  • Common wire required for heat pumps, heat-only, cool-only, three-wire zone valves and Apple HomeKit.
  • 2.4 GHz Wi-Fi, Sensi app and an account are required for connected setup and remote access.

Limitations & exclusions

  • Millivolt and economizer applications are not supported by the exact-model selection chart.

Check before you buy

  1. Compare the installed equipment voltage, stage count and terminal functions with the installation manual before selecting this model.
  2. Check the full model and terminal labels in the Sensi app’s installation workflow, including the common-wire requirement for the equipment type.
  3. For separate heating and cooling transformers, compare the internal RH/RC jumper with the manufacturer wiring diagram.
Manufacturer documentation (2)

Use these documents to compare your exact model and configuration.

Overview

Wi-Fi thermostat with app scheduling for conventional systems up to 2H/2C and heat-pump systems up to 4H/2C, subject to wiring and common-wire requirements.

Sensi provides app-based scheduling, keypad lockout and adjustable temperature limits. The specification sheet separates conventional heat/cool installations that can use power sharing from applications that require a common wire. The installation guide covers model identification, Wi-Fi setup and equipment configuration.

Selection and installation

Use the linked manufacturer documents to compare the exact model, equipment configuration and installation requirements before ordering.

Product details

SKU
907755
Model / MPN
1F87U-42WF
Condition
New
Lifecycle
Legacy

Specifications

Power sources
Conventional heat/cool: battery with power sharing or hardwired common; heat pump, heat-only and cool-only: hardwired common
Supply voltage
20–30 VAC, 50/60 Hz
Contact ratings
1.5 A per terminal; 2.5 A combined maximum
Stage modes
Conventional: up to 2H/2C; heat pump: up to 4H/2C including auxiliary heat
Scheduling modes
7-day, non-programmable and geofencing options
Schedule periods per day
Up to 8
Setpoint range
45–99 °F (R-4552-15 specification)
Operating temperature
32–105 °F
Operating humidity
90% RH maximum, non-condensing
Keypad lockout
Total keypad lockout through Sensi app
Setpoint limits
Adjustable minimum/maximum limits
Dual transformer support
Yes; follow the internal RH/RC jumper instructions
Millivolt support
Not listed as compatible in the exact-model selection chart
Remote sensor support
No remote sensor option listed in R-4552-15
Changeover modes
Automatic changeover available
Dimensions
5.88 in W × 3.75 in H × 1.00 in D

Documents & downloads