
Honeywell Home RTH6580WF
Score: 75/100
Emerson Sensi ST55
Score: 72/100Rankings

The Honeywell Home RTH6580WF is an affordable Wi-Fi thermostat that offers solid basic scheduling and broad system compatibility. Its main drawbacks are the lack of geofencing, auto-learning, and the need for a C-wire. It is best suited for budget-conscious homeowners with standard 24 V HVAC systems who want voice-assistant control.

Emerson Sensi ST55 provides a 5-inch LED touchscreen, broad smart-home compatibility, and geofencing-driven energy savings, all at an affordable price. Limitations include the need for a C-wire, 2.4 GHz-only Wi-Fi, and lack of built-in room sensors. Ideal for DIY homeowners seeking a versatile, budget-friendly thermostat.
| Attribute | ![]() | ![]() |
|---|---|---|
1 years | 3 yearsbest | |
— | 5 inchbest | |
| ↓ lower better | 0.544 kg | 0.386 kgbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
General(2) | ||
HVAC Compatibility | Gas/oil/electric heat with central AC, heat pump (with/without backup/aux heat), heat only (with/without fan), cool only, multi-stage up to 2 heat/2 c | Various (single to multi-stage) |
Warranty (years) | 1 years | 3 years |
Connectivity(1) | ||
Smart Home Integration | Alexa, Google Assistant, Samsung SmartThings, IFTTT, Bonomi, Wink, Stringify | Alexa, Google Assistant, Apple HomeKit, Samsung SmartThings |
Power & Installation(1) | ||
Power Source | 24 V | 20-30 VAC |
Display(1) | ||
Display Type | Backlit digital | LED touchscreen |
Features(1) | ||
Geofencing | false | true |
Build & Design(2) | ||
Device Weight (kg) | 0.544 kg | 0.386 kg |
Device Dimensions (H×W×D) (mm) | 147x89x38 mm | 25.4×149.35×95.25 mm mm |

Products in the top-left offer the best value (high score, low price).

Professional reviewers consider the Honeywell RTH6580WF a solid budget smart thermostat that delivers essential Wi-Fi functionality without the expense of premium models. They commend its reliable build, ENERGY STAR efficiency, and broad system compatibility, while noting the absence of geofencing, auto-learning, and the need for a C-wire as drawbacks.
Everyday users generally praise the thermostat for its easy installation, straightforward Wi-Fi setup, and noticeable energy savings. Common frustrations revolve around wiring requirements, occasional app or connectivity glitches, and the lack of automatic schedule learning.



Professional reviewers commend the Sensi ST55 for its straightforward DIY installation, ENERGY STAR efficiency and the claimed 23% energy savings, as well as its compliance with Title 24 and robust smart-home integration. However, they point out the need for a c-wire to unlock full functionality and the limitation to a 2.4 GHz Wi-Fi band.
Homeowners and renters alike praise the thermostat's quick setup, remote app control, energy-saving reports, and reliable fan circulation. Recurring complaints focus on occasional Wi-Fi drops, the necessity of a c-wire for some systems, and the lack of a built-in room sensor or precise humidity control.