Ecobee SmartThermostat Premium Review 2026 — After 3 Months Real Testing

Ecobee SmartThermostat Premium vs Nest — 2025 Comparison

What's In the Box

• Ecobee SmartThermostat Premium (display unit)
• 1× SmartSensor (room sensor) — this is the key differentiator
• Power Extender Kit (PEK) — enables installation without a C-wire
• Wiring labels and installation tools
• Mounting plate and screws

Installation

We installed without professional help in 42 minutes. The Ecobee app guides you through every step with clear diagrams. The Power Extender Kit is what makes this easier than Nest in older homes — it adds the equivalent of a C-wire using existing thermostat wiring, so no rewiring is needed.

1. Turn off the HVAC circuit breaker
2. Photograph the existing thermostat wiring
3. Install the PEK at the HVAC unit (15 minutes — requires access to the air handler)
4. Mount the Ecobee backplate and connect wires per app guidance
5. Attach the display unit
6. Restore power and complete app setup (10 minutes)

The Room Sensor — Ecobee's Key Differentiator

The included SmartSensor is what separates Ecobee from every competitor. Here's the problem it solves: your thermostat is mounted in the hallway. The hallway is cold. The thermostat heats the hallway to 21°C. Meanwhile, the living room where you're actually sitting is 23°C — too warm — because the hallway reading doesn't reflect where you are.

With the room sensor placed in the living room, Ecobee heats to the actual temperature where you are — not a cold draught-prone corridor. In our test, this accounts for approximately 8% of the total energy saving.

Additional sensors ($39 each) can be placed in any room. Set Ecobee to follow whichever sensor is in a room with motion detected — it heats the rooms being occupied, not the whole house.

Energy Savings: Our Real Data

We tracked heating bills for 3 months before installation, then 3 months after. Both periods were similar outdoor temperature ranges (normalised for weather using degree-days). We tested in a 3-bed semi-detached home with a gas boiler.

The 17% saving at £102/month average = £17.34/month = £208/year. The Ecobee at £199 / $250 pays for itself in under 12 months.

HomeKit, Alexa, and Google Home

Ecobee supports all three — simultaneously. This is unusual. Most thermostats force you to choose. With Ecobee you can:

• HomeKit: Temperature appears in the Home app, works with HomeKit automations, adjustable via Siri
• Alexa (built-in): The thermostat has a built-in Alexa microphone — you can talk to Alexa at the thermostat itself
• Google Home: Temperature control via Google Assistant voice commands

The HomeKit integration is particularly valuable — older Nest models did not support HomeKit, though the Nest Learning Thermostat 4th Gen added Apple Home support via Matter. If you're in the Apple ecosystem, Ecobee is the only quality thermostat choice.

Display and Interface

The 3.5" touchscreen is responsive and readable at a glance. The home screen shows: current temperature, set temperature, current mode (heating/cooling/off), and occupancy. Pressing the screen shows weather, room sensor temperatures, and quick controls. The design is pleasant but utilitarian — this is not a design statement like Nest.

The Ecobee app is well-designed. Energy reports show runtime by day, week, and month. You can see exactly when heating ran and for how long.

What We Didn't Like

• Design: Nest is significantly more attractive. If the thermostat is in a prominent location in a well-decorated home, this matters.
• PEK installation: Requires access to the air handler unit — this is in a cupboard or utility room and involves more work than a straight swap. If you're uncomfortable with this, hire an HVAC engineer for a 30-minute job.
• Room sensor placement: The sensor works best mounted at head height — adhesive-mounted on a wall or bookshelf. Getting it in the right position takes some experimenting.

Ecobee vs Nest — Summary

Final Verdict