Smart Thermostat Buying Guide: Ecobee vs Nest vs Honeywell for NH Homes

Smart thermostats are one of the highest-payoff HVAC upgrades a New Hampshire homeowner can make. NHSaves offers an $85 rebate on qualifying installs paired with a heat pump, and the energy savings from automated scheduling and occupancy sensing typically pay back the unit cost within one to two heating seasons. The harder question is which brand and model to choose.

This guide compares the three major smart thermostat lines (Ecobee, Nest, Honeywell Home), the considerations specific to NH homes, and how to choose between them.

Why a smart thermostat matters in NH

Two reasons specific to NH:

1. Long heating season. Heating runs roughly seven months a year in southern NH. Every percentage point of efficiency improvement compounds across thousands of hours of operation.
2. Heat pump compatibility matters. NH is one of the leading states for heat pump adoption. Heat pumps require specific thermostat configuration to avoid expensive aux heat. Smart thermostats handle this; basic thermostats often do not.

For background on why setbacks matter (and why they work differently with heat pumps), read: Should You Setback Your Thermostat? and Thermostat Setbacks.

The three major brands

Ecobee

Canadian company, smart thermostat specialist since 2007. Strongest remote sensor ecosystem. Best fit for homes with hot or cold rooms that the central system does not serve evenly. Read our deep dives: Ecobee Smart Thermostats and Improve Air Quality with Ecobee Smart Thermostats.

Google Nest

Acquired by Google in 2014. Strong learning behavior, polished Google Home integration. Best fit for homes that want minimal manual programming and broader Google smart home integration. Read: Nest Smart Thermostat.

Honeywell Home (Resideo)

Long heritage in HVAC controls. Very reliable hardware, strong heat pump support, often the easiest install on older NH systems. Less flashy than Ecobee or Nest but very capable.

Ecobee model comparison

Smart Thermostat Premium

Top of the line. Includes:

• Built-in air quality sensor (CO2 and VOC monitoring; see this post for what it does)
• Built-in voice control (Alexa)
• Spotify support
• Premium display, largest screen
• Remote sensor support (SmartSensors)
• Smart Home/Away (geofencing)
• Eco+ for additional optimization

Best for: homes where indoor air quality is a priority, or homeowners who want the highest-end experience.

Smart Thermostat Enhanced

Mid-tier; the best value in the Ecobee lineup for most NH homes. Same scheduling, sensors, and equipment compatibility as Premium, without the air quality sensor or built-in voice.

• Remote sensor support (SmartSensors)
• Smart Home/Away (geofencing)
• Eco+ for additional optimization
• Full equipment compatibility (heat pumps, multi-stage, dual-fuel)

Smart Thermostat Lite

Entry level. Smart features and Wi-Fi without remote sensor support.

• Best for: simple single-zone systems, rentals, situations where remote sensors are not needed

Nest model comparison

Nest Learning Thermostat (4th generation)

The flagship. Distinct round metallic design, learning behavior, occupancy sensing, hardware temperature sensing.

• Self-learning schedule (the original differentiator)
• Home/Away Assist (geofencing + motion sensing)
• Energy History reports
• Heat pump and dual-fuel compatible (correct configuration matters)
• Polished Google Home integration

Nest Thermostat (budget)

Simpler hardware, less expensive. No learning behavior, no remote sensors. Adequate for simple single-zone gas furnace systems.

Honeywell Home model lineup

Honeywell's smart thermostat lineup includes the T9 (with remote sensors, Wi-Fi, smart home integration) and the T6 Pro (more basic Wi-Fi thermostat with strong heat pump support). The T9 in particular is a strong Ecobee Enhanced competitor for households that prefer Honeywell's interface.

Heat pump compatibility: the make-or-break factor

If your home has or will have a heat pump, the smart thermostat must be configured correctly to avoid running expensive aux heat unnecessarily. Critical configuration items:

• Reversing valve wire (O or B): the thermostat must be set to the correct wire that activates cooling mode
• Compressor lockout temperature: below this outdoor temperature, only aux heat runs (typical: 15 to 30°F)
• Aux heat lockout temperature: above this outdoor temperature, aux heat is locked out so the heat pump must handle the load alone (typical: 30 to 40°F)
• Dual-fuel changeover: for heat pump + fossil-fuel furnace pairings, the outdoor temperature at which the system switches
• Stage timing: how long the heat pump runs before aux heat engages for setpoint recovery

Read: Ecobee Aux Heat Runtime Alert for what aux heat is and how to tell if your thermostat is configured correctly.

The C wire question

Modern smart thermostats need continuous low-voltage power. The wire that provides this is called the C wire (common). Many older NH homes do not have a C wire at the thermostat location. Three solutions:

• Run a new C wire from the air handler or boiler. Best long-term solution when accessible.
• Use a power adapter at the air handler. Ecobee includes a Power Extender Kit (PEK) in the box; for Nest, the Nest Power Connector is a separately sold accessory that does the same job.
• Power-stealing through an unused conductor. Works on most systems but can cause intermittent issues on some equipment.

The decision tree

Question 1: Heat pump or fuel-burning system?

• Heat pump: Ecobee Enhanced, Nest Learning, or Honeywell T9 are all strong choices. Professional installation matters more than brand choice.
• Gas/propane/oil furnace or boiler: any of the three brands work. Brand becomes a personal preference question.

Question 2: Hot or cold rooms?

• Yes: Ecobee Enhanced or Premium with remote sensors. The Ecobee SmartSensor ecosystem is the strongest remote sensor system.
• No: any brand works.

Question 3: Indoor air quality priority?

• Yes: Ecobee Premium (built-in CO2/VOC sensor) or pair any thermostat with a dedicated IAQ monitor.
• No: Enhanced, Nest Learning, or Honeywell T9 will each serve you well.

Question 4: Smart home ecosystem preference?

• Apple HomeKit-focused household: Ecobee has the strongest HomeKit support of the three.
• Google Home-focused household: Nest is the natural fit.
• Amazon Alexa-focused household: all three work; Ecobee Premium has Alexa built into the thermostat hardware.

Question 5: Budget?

• Tight: Ecobee Lite, Nest Thermostat (budget), or Honeywell T6 Pro
• Standard: Ecobee Enhanced, Nest Learning, or Honeywell T9
• Premium: Ecobee Premium

What about geofencing?

All three brands offer geofencing through their respective apps (Ecobee Smart Home/Away, Nest Home/Away Assist, Honeywell Home geofence). The implementations are similar in practice. Read our deep dive: Smart Thermostat Geofencing.

Installation matters

A smart thermostat installed by someone who does not understand heat pump configuration is worse than no smart thermostat at all. Common issues:

• Reversing valve wired backward (heat pump runs cooling when it should run heating)
• Aux heat lockout left at default setting (expensive electric resistance runs unnecessarily)
• Compressor lockout set wrong for the heat pump's actual capacity
• C wire issues causing intermittent power loss

For a heat pump system, the value of professional installation typically exceeds the cost. For a simple gas furnace with a C wire already present, DIY is reasonable.

NHSaves rebate

NHSaves offers an $85 rebate on qualifying smart thermostat installations paired with a qualifying heat pump. Check current eligibility through your utility before purchase. The rebate effectively reduces the unit cost to under $200 for most major models.

What to do next

1. Confirm your current system type (heat pump, gas/propane/oil furnace, boiler with hydronic heat)
2. Verify you have or can run a C wire to the thermostat location
3. Walk through the decision tree above
4. If you have a heat pump, plan on professional installation for proper configuration
5. Apply for the NHSaves rebate at install time

Schedule a smart thermostat installation

For smart thermostat installation in southern New Hampshire, contact A.J. LeBlanc Heating. See our Smart Thermostat Installation service page for details. Serving New Hampshire families since 1928.

Frequently Asked Questions

Which smart thermostat is best for a heat pump?

Any of the three major brands (Ecobee Enhanced/Premium, Nest Learning, Honeywell T9) handle heat pumps well. The installation quality (proper configuration of compressor lockout, aux heat lockout, reversing valve wire) matters more than the brand choice.

Do I need professional installation?

For a heat pump or dual-fuel system, professional installation usually pays for itself in correct configuration alone. For a simple gas furnace with a C wire, DIY is reasonable.

What if my home does not have a C wire?

Ecobee includes a Power Extender Kit (PEK) that solves this in most cases; for Nest, the separately sold Nest Power Connector does the same job. Either device installs at the air handler and provides power without running a new wire to the thermostat.

How much does a smart thermostat save?

Real-world savings are typically about 8 to 15 percent on heating and cooling costs, depending on your habits, schedule, and system type. Less for households that already used programmable thermostats consistently. More for heat pump households with correctly configured controls.

Can I keep using my current programmable thermostat?

Yes, but you give up automated scheduling, occupancy sensing, remote control, and (for heat pumps) the algorithmic aux heat management that produces real savings. The payback period on a smart thermostat is short enough that most NH homes benefit from the upgrade.