Smart Electric Heater 2026: Buying Guide and Energy Savings

Smart electric heaters: the inertia revolution

Electric heating equips over 35% of French homes and a significant share across northern Europe. For decades, these heaters had a reputation for being uncomfortable and energy-hungry. Inertia technology combined with WiFi connectivity has completely changed things. Modern connected electric heaters can reduce your heating bill by 30 to 40% compared to a classic convector, while providing significantly superior thermal comfort.

This guide covers everything: inertia technologies, connectivity, how to optimise programming, and which model suits your home and budget. See also our smart home energy saving guide and our smart thermostat guide.

Fluid inertia vs dry stone inertia

Fluid inertia: reactivity and even heat

In a fluid inertia heater, an electric resistance heats a liquid that accumulates heat, then transfers it evenly through the fins. Advantages: rapid heat-up (15-20 min), even heat, moderate inertia (room stays warm 1-2h after switching off). Ideal for living rooms and dining areas. Leading brands: Thermor Equateur 4, Atlantic Oniris, Sauter Orisio.

Refractory stone inertia: the ultimate comfort

Dry inertia heaters use refractory stone blocks (ceramic, synthetic granite or soapstone) that store heat like a central water radiator. Heat is released gradually through infrared radiation. Advantages: high thermal inertia (room stays warm 3-5h after switching off), very comfortable radiant heat, maximum savings with off-peak electricity. Ideal for bedrooms. Leading brands: Noirot Axial, Elnur Gabarron, Campa Campaver.

Essential connected features

Room-by-room programming

This is the feature that generates the most savings. With a connected heater, you programme separate time slots per room based on your actual habits. Optimal example: bedroom at 18°C at night, 16°C during the day; living room at 21°C from 5:30pm to 10pm, 16°C otherwise; bathroom at 20°C only during shower hours.

Open window detection

A classic heater keeps heating when you open the window to air a room — you're heating outdoor air. Open window detection uses temperature drop analysis: if temperature falls more than 3°C in 3 minutes, the heater switches to standby. Which? estimates this feature alone can save 5-8% on annual heating bills.

Best models comparison 2026

Model	Technology	Connectivity	App	Power	Price	Score
Thermor Equateur 4	Fluid inertia	WiFi + Pilot wire	Cozytouch (excellent)	500-2500W	£160-360	9/10
Atlantic Oniris	Fluid inertia	WiFi + Pilot wire	Cozytouch	500-2500W	£160-360	9/10
Noirot Axial 4	Dry stone inertia	WiFi	Mes Radiateurs	500-2000W	£270-540	8.5/10
Sauter Orisio	Fluid inertia	WiFi + Pilot wire	Cozytouch	500-2000W	£150-340	8/10
Elnur Gabarron	Dry inertia	WiFi	Elnur Home	1000-3000W	£225-495	8/10

Thermor Equateur 4: our top pick

The Thermor Equateur 4 is the best-selling connected heater in France. Its Cozytouch app is one of the best on the market: clear interface, intuitive programming, Google Home and Alexa compatibility, open API for Home Assistant. Open window detection included. See Thermor Equateur 4 on Amazon

Real savings: the numbers

A 2024 consumer study covering 500 households who installed connected heaters found an average saving of 32% on the electric heating bill in the first year. Households that best optimised programming (zone-based, with window detection and off-peak management) achieved up to 45% savings.

Concrete example: 65m² flat with 4 convector heaters, annual heating bill £1,100. After replacement with 4 well-programmed inertia connected heaters: £660-730. Saving: £370-440/year. Return on investment (4 heaters at £255 each = £1,020 total): 2.5-3 years.

Frequently Asked Questions

What is the difference between a WiFi connected heater and a heater with pilot wire?

A WiFi heater connects directly to your internet network and is controlled via a smartphone app — no additional wiring needed. The pilot wire is a French wiring system that allows a central programmer or Linky meter to control multiple heaters simultaneously via a dedicated electrical signal. The two technologies are not mutually exclusive: the best connected heaters (Thermor Equateur 4, Atlantic Oniris) integrate both, offering both app control and compatibility with an existing pilot wire installation.

How much does a 1500W connected electric heater cost to run?

A 1500W heater does not heat continuously — a well-programmed inertia heater runs on average 4-6 hours per day in a well-insulated room. That is 6-9 kWh per day. At current electricity prices (around £0.27/kWh in the UK), this represents £1.60-2.40 per day in winter, or £215-325 for a 5-month heating season. An equivalent convector without inertia would consume 30-40% more for the same result.

Are connected heaters compatible with the Linky smart meter?

Yes, heaters compatible with 6-order pilot wire (which is the case for most premium connected models) can receive orders directly from the Linky meter if you have subscribed to the Pilot Wire option with your energy supplier. The Linky can then automatically send Eco orders during peak hours and Comfort orders during off-peak hours. For pure WiFi heaters, off-peak management is done in the app (manual time programming).

Do you need an electrician to install a connected electric heater?

For a simple replacement of an old heater on an existing socket or dedicated circuit, installation is accessible to a beginner DIYer. The heater connects to the existing circuit (5 wires: Phase, Neutral, Earth, and 2 pilot wire wires). However, if you are creating a new circuit from the distribution board, use a certified electrician — this is mandatory to comply with standards and for your home insurance.

Which connected heater brand is the most reliable in 2026?

Thermor and Atlantic (same group) have dominated the French market for decades and have the best reputation for reliability and after-sales service. Their Cozytouch app is one of the few to offer an open API for Home Assistant. Noirot (Muller Intuitiv group) comes second for build quality, especially on dry inertia models. Sauter offers the best value for money at the entry level. Avoid unknown brands sold only on marketplaces: apps are often abandoned after 2-3 years, making the heater partially unusable.