Smart Thermostats / Google Nest Learning Thermostat (4th gen) vs Sensi Lite (ST25)
Google Nest Learning Thermostat (4th gen) vs Sensi Lite (ST25)
Google Nest Learning Thermostat (4th gen)
The only one that really learns your schedule, and it usually needs no C wire.
Wins overall by 2.5 points
Quick Verdict
The Google Nest Learning Thermostat (4th gen) takes this by a clear 2.5 points. The only one that really learns your schedule, and it usually needs no C wire. The Sensi Lite (ST25) only makes sense if it wins on a category you care about more than the total.
The Google Nest Learning Thermostat (4th gen) and Sensi Lite (ST25) are both closely matched smart Thermostat models, and the Sensi Lite (ST25) is $161 cheaper than the Google Nest Learning Thermostat (4th gen) ($79 vs $239.99). On Multi-Room Sensing, the Google Nest Learning Thermostat (4th gen) leads (7.5 vs 1.0/10) — remote sensors: included or extra, how many pair, and whether they read occupancy or only temperature. On Smart Home Integration, the Google Nest Learning Thermostat (4th gen) leads (8.5 vs 4.0/10) — matter, Apple Home, Alexa and Google support — and how much each one actually exposes. On Scheduling & Learning, the Google Nest Learning Thermostat (4th gen) leads (9.5 vs 5.0/10) — learning, geofencing, away detection and how much of it works without babysitting the app. Overall, the Google Nest Learning Thermostat (4th gen) scores 8.4/10 across our 8 scoring categories versus 5.9/10 for the Sensi Lite (ST25). Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Google Nest Learning Thermostat (4th gen) | Sensi Lite (ST25) |
|---|---|---|
| Price | $239.99 | $79.00 |
| Release Year | 2024 | 2023 |
| System Voltage | Low voltage 24V only — gas, electric, oil, forced air, heat pump and radiant. Will not run 120/240V baseboard or radiant electric heat | Low voltage 24VAC (20-30VAC, 50/60Hz). Not for 120/240V line-voltage heat |
| C-Wire Required | Not in most homes. Google's patented Power Sharing borrows power from the other wires, and the store page claims roughly 85% system compatibility — but it also states heating-only, cooling-only, zone-controlled and heat pump systems need a Nest Power Connector or a C wire | Mostly no — and Copeland is unusually honest about the exception. Its own product title reads 'C-Wire Not Required, Except On Heat/Cool Only and Heat Pump Systems', and the manual confirms heat-only, cool-only and heat pump systems all need a common wire |
| Adapter / Power Kit Included | No — the Nest Power Connector is a separate $24.99 accessory, not in the box | No adapter is included, and none is needed on the majority of conventional systems |
| Heating & Cooling Stages | Up to 3 stages of heating and cooling, plus fan speed control | 2H/1C or 1H/2C, single and multi-stage, gas, oil or electric. Ten terminals: R, C, W/E, G, Y, O/B, Y2, W2, L and AUX, rated 1.5A per terminal and 2.5A total |
| Heat Pump & Aux Heat | Yes, including auxiliary and emergency heat | Yes — heat pump 2H/1C, and the manual lists dual fuel and zone valve configurations. A heat pump does need a C wire on this model |
| Humidifier / Ventilator Terminals | Humidifier, dehumidifier and ventilation (HRV/ERV) systems all supported — the widest accessory coverage of the Nest line | None — no humidifier, dehumidifier or ventilator output |
| Remote Sensors | One Nest Temperature Sensor (2nd gen) included; up to 6 more. Google states all generations of the sensor work with this model | None. Copeland states only the Sensi Touch 2 works with Sensi Room Sensors |
| Occupancy Detection | Soli radar senses presence and proximity at the thermostat itself, plus phone-location Home/Away. The Nest Temperature Sensor reads temperature only — it does not detect occupancy | None. Away control is geofencing from your phone only |
| Matter Support | Matter-certified, so it appears in any Matter app including Apple Home. Google does not publish a Thread radio for this model | No |
| Voice & Smart Home Platforms | Google Home app (required for setup and control — the standalone Nest app is retired), Amazon Alexa, Apple Home via Matter | Sensi app, Amazon Alexa, Google Assistant, Samsung SmartThings. No Apple Home |
| Utility Rebates & Demand Response | Rush Hour Rewards, run by Renew Home with your energy provider, plus Nest Renew Energy Shift. Google's own help page says Rush Hour Rewards makes adjustments 'typically up to 4°F' for 3-4 hours during demand events; enrolment is through the Google Home app | ENERGY STAR certified, rated for about 23% HVAC energy savings, and stocked across US utility rebate marketplaces |
| Account or Subscription Needed | No subscription. Learning, Savings Finder and Eco when Away are free, but a Google account and the Google Home app are mandatory | No subscription. A free Sensi account is required |
| Warranty | 24 months | 36 months |
| Colors | Polished Silver, Polished Obsidian, Polished Gold | Black (ST25), White (ST25W) |
Category Scores
C-Wire Freedom
The Google Nest Learning Thermostat (4th gen) leads clearly here, 8.5 against 8.0 — a 0.5-point margin on how likely this thermostat is to run on the wiring you already have — whether it needs a common wire, and whether the workaround is in the box, sold separately, or an electrician's visit. The single biggest cause of returns in this category.. If that is what you are buying for, the Sensi Lite (ST25) does not close the gap elsewhere.
HVAC Coverage
The Google Nest Learning Thermostat (4th gen) leads clearly here, 9.5 against 6.5 — a 3.0-point margin on stages of heating and cooling, heat pump and auxiliary heat handling, and humidifier / dehumidifier / ventilator terminals. If that is what you are buying for, the Sensi Lite (ST25) does not close the gap elsewhere.
Multi-Room Sensing
The Google Nest Learning Thermostat (4th gen) leads clearly here, 7.5 against 1.0 — a 6.5-point margin on remote sensors: included or extra, how many pair, and whether they read occupancy or only temperature. If that is what you are buying for, the Sensi Lite (ST25) does not close the gap elsewhere.
Smart Home Integration
The Google Nest Learning Thermostat (4th gen) leads clearly here, 8.5 against 4.0 — a 4.5-point margin on matter, Apple Home, Alexa and Google support — and how much each one actually exposes. If that is what you are buying for, the Sensi Lite (ST25) does not close the gap elsewhere.
Scheduling & Learning
The Google Nest Learning Thermostat (4th gen) leads clearly here, 9.5 against 5.0 — a 4.5-point margin on learning, geofencing, away detection and how much of it works without babysitting the app. If that is what you are buying for, the Sensi Lite (ST25) does not close the gap elsewhere.
Display & On-Device Control
The Google Nest Learning Thermostat (4th gen) leads clearly here, 9.0 against 5.0 — a 4.0-point margin on screen quality and how much you can do at the wall instead of in the phone app. If that is what you are buying for, the Sensi Lite (ST25) does not close the gap elsewhere.
Installation
The Sensi Lite (ST25) leads clearly here, 8.5 against 8.0 — a 0.5-point margin on wiring complexity, guided setup, and how likely a DIY install is to end in a service call. If that is what you are buying for, the Google Nest Learning Thermostat (4th gen) does not close the gap elsewhere.
Value
The Sensi Lite (ST25) leads clearly here, 9.0 against 6.5 — a 2.5-point margin on what the money buys once accessories, adapters and sensors are added in. If that is what you are buying for, the Google Nest Learning Thermostat (4th gen) does not close the gap elsewhere.
Best For
Choose the Google Nest Learning Thermostat (4th gen) if…
- • Multi-Room Sensing matters most to you — the Google Nest Learning Thermostat (4th gen) scores 7.5/10 here (remote sensors: included or extra, how many pair, and whether they read occupancy or only temperature).
- • Smart Home Integration matters most to you — the Google Nest Learning Thermostat (4th gen) scores 8.5/10 here (matter, Apple Home, Alexa and Google support — and how much each one actually exposes).
- • Scheduling & Learning matters most to you — the Google Nest Learning Thermostat (4th gen) scores 9.5/10 here (learning, geofencing, away detection and how much of it works without babysitting the app).
- • Display & On-Device Control matters most to you — the Google Nest Learning Thermostat (4th gen) scores 9.0/10 here (screen quality and how much you can do at the wall instead of in the phone app).
- • HVAC Coverage matters most to you — the Google Nest Learning Thermostat (4th gen) scores 9.5/10 here (stages of heating and cooling, heat pump and auxiliary heat handling, and humidifier / dehumidifier / ventilator terminals).
Choose the Sensi Lite (ST25) if…
- • You want to spend less — it's $161 cheaper.
- • Your main use case is budget.
Pros & Cons
Google Nest Learning Thermostat (4th gen)
Pros
- +The only thermostat here that genuinely writes its own schedule — install it and you can never open the app again
- +Runs without a C wire in most homes, which no ecobee, Sensi Touch 2, Amazon or Honeywell X-series model here can claim
- +Three stages plus humidifier, dehumidifier and ventilator terminals — the broadest HVAC coverage in this set alongside the ecobee Premium
- +Bundles a temperature sensor at a price where the $199.99 ecobee Enhanced bundles none
Cons
- −'No C wire required' carries a long asterisk: Google's own page lists heating-only, cooling-only, zone-controlled and heat pump systems as needing the $24.99 Nest Power Connector, which covers a large share of US homes
- −The bundled Nest Temperature Sensor is temperature-only — it cannot tell whether a room is occupied, which every ecobee SmartSensor can
- −Setup and control are locked to a Google account and the Google Home app; the old Nest app and Works with Nest are gone
- −Rush Hour Rewards pays you to let the utility push your setpoint by up to about 4°F for three to four hours at a time
- −Highest list price here at $279.99, on a 2-year warranty that both ecobee and Mysa beat
Sensi Lite (ST25)
Pros
- +One of only three thermostats here that runs without a C wire on ordinary conventional systems, and by far the cheapest
- +Ten terminals including AUX and L, with dual-fuel and zone-valve support that no other sub-$100 model here documents
- +Copeland spells out the C-wire exception in the product title itself instead of burying it in a compatibility checker
- +$79 street against $89.99 list, with heavy utility-marketplace rebate availability
Cons
- −The C-wire exemption evaporates exactly where it matters: heat-only, cool-only and heat pump systems all need one
- −No Apple Home and no Matter, so it is Alexa, Google or the Sensi app and nothing else
- −No room sensor support at all — Copeland reserves Sensi Room Sensors for the Touch 2
- −No humidifier or ventilator terminals despite the generous terminal count
- −No trim plate and no battery backup — the manual states there is no battery option, so a blown 24V fuse leaves the screen dark
Shop by Need
FAQs
Is the Google Nest Learning Thermostat (4th gen) or Sensi Lite (ST25) better overall?+
Based on our 8-category scoring, the Google Nest Learning Thermostat (4th gen) comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Multi-Room Sensing, the Google Nest Learning Thermostat (4th gen) or the Sensi Lite (ST25)?+
The Google Nest Learning Thermostat (4th gen) scores higher on Multi-Room Sensing (7.5/10 vs 1.0/10) — remote sensors: included or extra, how many pair, and whether they read occupancy or only temperature.
Which is better for Smart Home Integration, the Google Nest Learning Thermostat (4th gen) or the Sensi Lite (ST25)?+
The Google Nest Learning Thermostat (4th gen) scores higher on Smart Home Integration (8.5/10 vs 4.0/10) — matter, Apple Home, Alexa and Google support — and how much each one actually exposes.
Which is better for Scheduling & Learning, the Google Nest Learning Thermostat (4th gen) or the Sensi Lite (ST25)?+
The Google Nest Learning Thermostat (4th gen) scores higher on Scheduling & Learning (9.5/10 vs 5.0/10) — learning, geofencing, away detection and how much of it works without babysitting the app.
Which is better for Display & On-Device Control, the Google Nest Learning Thermostat (4th gen) or the Sensi Lite (ST25)?+
The Google Nest Learning Thermostat (4th gen) scores higher on Display & On-Device Control (9.0/10 vs 5.0/10) — screen quality and how much you can do at the wall instead of in the phone app.
Is the Google Nest Learning Thermostat (4th gen) worth the price difference over the Sensi Lite (ST25)?+
The Sensi Lite (ST25) is the cheaper option at $79 versus $239.99. Whether the pricier model is "worth it" depends on how much you value its lead in Multi-Room Sensing.
Which is better suited to my use case?+
The Google Nest Learning Thermostat (4th gen) is the better fit if you mainly care about multi-room or matter. The Sensi Lite (ST25) is the better fit for budget.
What's the warranty on the Google Nest Learning Thermostat (4th gen) vs the Sensi Lite (ST25)?+
The Google Nest Learning Thermostat (4th gen) ships with a 24-month warranty; the Sensi Lite (ST25) ships with a 36-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Premium Option
ecobee Smart Thermostat Premium (EB-STATE6-01) — $259.99
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.