Best Electric Combi Boilers

Overview

From UK-based manufacturer Heatrae Sadia, the Electromax is a combined electric heating and hot water solution designed for homes without access to mains gas.

Rather than producing hot water instantaneously, the Electromax combines an electric flow boiler with an integrated hot water storage cylinder, delivering a reliable and practical electric alternative for small to medium-sized homes.

Is the Electromax right for my home?

The Electromax system consists of two independently operating components:

• An electric flow boiler that supplies heat to radiators or underfloor heating (model dependent)
• A separate hot water cylinder that provides mains-pressure hot water to taps and showers

Because these components work independently, homeowners can:

• Turn off central heating during summer without affecting hot water
• Maintain consistent hot water performance regardless of heating demand

This makes the Electromax a flexible option for year-round use.

Hot water performance and off-peak efficiency

The Electromax includes a 180-litre stainless steel hot water cylinder, housed within the unit’s casing.

Key benefits include:

• Designed to heat water during off-peak hours, making it ideal for Economy 7 tariffs
• Advanced technology
• Stored hot water available throughout the day
• A built-in boost function to heat additional water when required (typically within an hour)

This approach provides better hot water flow and pressure than direct electric systems, making it suitable for baths and showers in everyday use.

Controls and heating flexibility

Central heating is controlled via a programmable room thermostat, positioned away from the boiler unit. This can be used alongside thermostatic radiator valves (TRVs) to manage room-by-room temperatures.

The Electromax control panel allows users to:

• Select operating modes (hot water only, hot water boost, heating only)
• Set desired water temperatures
• Monitor system status

This gives homeowners straightforward control without unnecessary complexity.

Size and installation

The Electromax is a floor-standing, sealed-system unit, designed to fit neatly into standard domestic airing cupboards.

While larger than wall-mounted electric boilers, its integrated design eliminates the need for a separate hot water cylinder elsewhere in the property, helping to save space overall.

As a fully electric system, no flue is required, simplifying installation.

Warranty and reliability

Heatrae Sadia is well known for electric heating products, particularly in the hot water and storage cylinder market. The Electromax benefits from robust build quality and strong installer familiarity, making long-term maintenance straightforward.

Verdict

The Electromax is an excellent choice for homeowners who want:

• Reliable electric central heating
• Strong hot water performance from stored supply
• Compatibility with off-peak electricity tariffs
• Quiet, unobtrusive operation

While it requires more space than compact wall-mounted electric boilers, its hot water capability and efficiency with Economy 7 tariffs make it one of the most practical electric combi-style systems available for small to medium-sized homes.

Specification

Please select a model below to view its specifications.

• 6kW
• 9kW

Overview

From electric heating specialist Elnur, the Mattira MAC15 is a wall-mounted electric combi boiler designed to provide central heating and domestic hot water for small to medium-sized homes.

Developed as the successor to earlier Mattira models, the MAC15 focuses on compact design, advanced modulation, and efficient electricity use, making it a popular choice where space is limited and gas is unavailable.

Is the Mattira MAC15 right for my home?

The Mattira MAC15 is best suited to properties where compact size, safety, and controlled electricity usage are key priorities.

As a fully electric boiler, it:

• Produces no combustion gases
• Requires no flue
• Eliminates risks associated with fossil fuels such as gas, LPG, or oil

This makes it particularly suitable for flats, apartments, and well-insulated homes.

Efficiency and modulation technology

A standout feature of the Mattira MAC15 is its Smart Electronic Modulation (SEM) system.

SEM technology allows the boiler to:

• Continuously adjust output based on heating demand
• Take account of internal and external temperature conditions
• Avoid unnecessary energy consumption

By matching output closely to demand, the boiler delivers very high real-world efficiency and improved comfort levels compared with fixed-output electric boilers.

Controls and operation

The Mattira MAC15 features a clear, user-friendly digital display, allowing homeowners to:

• Monitor heating and hot water temperatures
• Select heating-only or hot-water-only modes
• View system status and settings

Unlike electric boilers with integrated hot water storage, the MAC15 prioritises controlled, efficient operation rather than high-volume hot water delivery. This makes it best suited to homes with modest hot water demand.

System compatibility and flexibility

The Mattira MAC15 can be used with:

• Standard wet-radiator systems
• Radiant floor heating
• Hybrid setups alongside renewable technologies such as solar thermal or heat pumps

This flexibility allows homeowners to integrate the boiler into broader low-carbon heating strategies if desired.

Size and installation

The Mattira MAC15 is a compact, wall-mounted boiler, designed for internal installation where space is limited.

Key considerations:

• Wall strength should be assessed, particularly when the unit is full
• Its compact size makes it ideal for cupboards, utility areas, or apartments
• No flue or external ventilation is required

Warranty and reliability

The boiler features a stainless steel internal cylinder, designed for corrosion resistance and long service life.

Warranty cover typically includes:

• 5 years on the stainless steel cylinder
• 2 years on remaining components

This provides reasonable long-term reassurance for homeowners investing in electric heating.

Verdict

The Mattira MAC15 is an excellent choice for homeowners who want:

• A compact, wall-mounted electric combi boiler
• Advanced modulation for efficient electricity use
• Safe, flue-free operationy
• Compatibility with modern low-carbon heating systems

While it is not designed for high hot-water demand, its efficiency, flexibility, and small footprint make it one of the best compact electric combi boilers available, particularly for flats and small to medium-sized homes.

Specification

Please select a model below to view its specifications.

• 3-12kW