The short version: The 3rd generation Nest Learning Thermostat (2015) is the classic round metal-and-glass Nest — Stainless Steel, Copper, or Black finishes, auto-schedule learning, and Farsight. At $270–290 CAD, it’s now an older design sitting alongside Google’s redesigned 4th-gen model, and pricing doesn’t always undercut the newer version by much. It still performs well; just compare current pricing before assuming it’s the budget pick.

Who It’s For

Works with central forced-air heating and cooling: gas, oil, or electric furnaces (single- and multi-stage), central AC, and standard-to-moderately-complex heat pump systems. It does not work with electric baseboard heat — Mysa, Sinopé, or Stelpro cover that in Canada.

Best fit for:
– Buyers who specifically want the classic round steel/copper/black look, discontinued in the 4th-gen redesign
– Google Home households wanting auto-scheduling without 4th-gen pricing, if a good deal is available
– Anyone replacing an existing 3rd-gen unit and wanting matching hardware across rooms

Skip it if you want the newest sensors and AI-driven scheduling, or if similarly-priced new 4th-gen stock is available — worth comparing directly since the design departure is substantial.

Design & Build

A 3.25-inch color display in a circular metal housing, available in Stainless Steel, Copper, and Black. Farsight lights up the display as you approach — a feature the base Nest Thermostat lacks, and one reviewers consistently call a nice, non-essential touch.

It’s distinctive wall hardware that has aged well even as Google has since moved to a larger-bodied design in the 4th gen.

Setup & Compatibility

C-wire situation: No C-wire required — uses the same power-harvesting approach as other Nest models, drawing a small charge from your HVAC system to maintain its battery.

System compatibility: Handles single- and multi-stage gas furnaces, central AC, and heat pump wiring including the O/B terminal for reversing valves and auxiliary/emergency heat — relevant for Canadian dual-fuel setups.

Known install-related complaints: Some buyers report a “W5 error” preventing Wi-Fi connection on a subset of units; Google has historically replaced affected devices under warranty. Several reviewers also note the in-box install directions are thinner than they’d like, though the app itself walks through wiring reasonably well.

App & Ecosystem

The auto-schedule learning is the signature feature: it observes your manual adjustments for the first one to two weeks and builds a schedule from the pattern. Works best for consistent routines; irregular work-from-home schedules can trip it up.

Ecosystem support:
– Google Assistant / Google Home: Full native integration
– Amazon Alexa: Supported
– Apple HomeKit: Not supported — a persistent limitation across all Nest generations

A commonly cited flaw involves the optional remote Nest Temperature Sensor: several reviewers and owners describe its response time as slow enough that HVAC runs noticeably past target temperature before the system catches up. Worth weighing against Ecobee’s SmartSensor system if room-by-room comfort matters to you.

Should You Buy 3rd Gen or Wait for 4th Gen Pricing?

The 4th-gen Learning Thermostat (2024) is a genuinely different product: larger glass display, redesigned base, bundled temperature sensor on some configurations, and Matter support. If new 3rd-gen stock is priced close to 4th-gen stock at Canadian retailers, the 4th gen is usually the better buy unless you specifically want the classic steel/copper/black aesthetic.

Price & Value

Nest Learning Thermostat (3rd Gen)
Price (CAD) $270–290
Warranty 2 years
Subscription required No

Sold through Best Buy, Home Depot, and Amazon.ca, generally as remaining/clearance stock rather than a current Google product line. See Smart Thermostat Rebates in Canada by Province for rebate eligibility — it’s ENERGY STAR certified and typically appears on most provincial utility qualifying lists, though amounts vary too much to state generally here.

Pros & Cons

Pros:
– Distinctive, well-regarded design in steel, copper, or black finishes
– Farsight display activation
– Auto-schedule learning works well for consistent routines
– Mature, well-tested HVAC compatibility

Cons:
– Older design now sitting alongside a substantially redesigned 4th-gen model
– No Apple HomeKit support
– Remote sensor response time criticized as slow by multiple reviewers
– A subset of units affected by a Wi-Fi connection (“W5”) error
– 2-year warranty, shorter than Ecobee’s 3-year

Nest models compared: Nest Thermostat, Nest Learning Thermostat (3rd Gen), and Nest Learning Thermostat (4th Gen), with features, price, and Canadian rebate eligibility

The Recommendation

Buy the 3rd Gen Learning Thermostat if you specifically want the classic steel/copper/black design and it’s priced meaningfully below current 4th-gen stock.

Buy the 4th Gen instead if pricing is close — you get a newer design, bundled sensor options, and Matter support for roughly the same money.

Consider Ecobee if HomeKit support or precise room-sensor performance matter more to you than the Nest aesthetic, and if provincial rebate eligibility is a priority. See Nest vs Ecobee: Which Should You Buy?

Frequently Asked Questions

Is the 3rd Gen Nest Learning Thermostat still worth buying over the 4th Gen in Canada?
Only if it’s noticeably cheaper. The 4th gen is a newer design with more current sensor tech; the 3rd gen mainly wins on price when discounted or on aesthetic preference.

Does the 3rd Gen support Apple HomeKit?
No. No Nest generation, including the 4th gen, supports HomeKit.

Does the 3rd Gen qualify for Canadian utility rebates?
Yes, it’s ENERGY STAR certified and typically appears on most provincial qualifying lists, though eligibility varies by utility. See Smart Thermostat Rebates in Canada by Province.

What’s the “W5 error” some owners report?
A Wi-Fi connectivity fault reported on a subset of units that prevents the thermostat from joining your network. Google has historically replaced affected units under warranty.

Does the 3rd Gen work with heat pumps common in Canadian homes?
Yes, including dual-fuel setups via the O/B terminal and auxiliary/emergency heat controls, though Ecobee offers more granular controls for complex cold-climate systems.

Does the 3rd Gen require a C-wire?
No, it uses power harvesting like other Nest models, though connecting a C-wire if available eliminates any risk of ghost calls.