Best Electric Combi Boilers (Electric-Only Guide)

Electric combi boilers are becoming a realistic heating option for more UK homes.

They suit properties without a gas supply, homes aiming for lower emissions and households that want simple installation with fewer moving parts.

This guide explains how electric combi boilers work, the types available, the advantages and drawbacks and who they are best suited for.

It also includes a clear overview of the models that are performing well in 2025 so you can decide which type is right for your home.

If you want to compare electric systems with modern gas options before deciding, you can also read our guide to the best combi boilers 2025.

The best electric combi boilers in 2025

Homeowners searching for the best electric combi boilers usually want one of the following:

• A compact unit that fits in smaller homes

• Reliable hot water performance for daily use

• Simple controls and low maintenance

• Good efficiency and stable running costs

• A suitable option for homes without a gas connection

The models below reflect those priorities. They are chosen because they are established, widely available and well suited to typical UK households.

1. Electric Heating Company Comet Combi

This is one of the most common electric combi units for small to medium homes.

It provides central heating and hot water from one compact unit and has simple controls that suit everyday use.

It is quiet in operation and designed to fit easily into most indoor spaces.

2. Heatrae Sadia Electromax

This is a flow boiler combined with a built-in cylinder.

It suits homes with higher hot water use, such as households with more than one bathroom.

The stored hot water allows better performance across multiple taps and maintains stable temperature during use.

3. Elnur Mattira MACC

This wall-mounted electric combi works well in flats and smaller houses.

It has flexible output ranges, straightforward digital controls and compatibility with smart thermostats.

It is also known for consistent efficiency, which helps keep running costs predictable.

4. Fischer EB Electric Combi

This is a higher-output electric combi designed for larger homes or those with a higher hot water demand.

It has strong flow performance, durable internal components and a longer expected lifespan.

It is often chosen for homes where a standard low-output electric combi would struggle.

5. Vaillant Eloblock Electric Boiler

This system boiler is often used in homes switching from gas to electric or those integrating solar.

It is a recognised brand option with reliable performance and modern controls and can suit a wider range of property sizes when paired with a cylinder.

What an electric combi boiler is and how it works

An electric combi boiler heats water using electrical elements instead of burning gas or oil.

Water is heated inside the unit and sent directly to taps and radiators.

There is no need for a flue, gas pipework or a separate hot water cylinder.

A typical electric combi is best suited to:

• Flats

• Small or medium houses

• Properties with one bathroom

• Homes without a gas connection

• Homes aiming for lower emissions

Electric boilers convert almost all the energy they use into heat.

This is why they are often listed with efficiency ratings of 99 to 100 percent at point of use.

Types of electric boilers

Although this guide focuses on electric combi boilers, there are other types that may suit different households.

Knowing the difference helps you choose the right system.

Electric combi

The most popular type. It provides heating and hot water from one unit and gives instant hot water with no need for a storage tank.

Best for smaller homes with standard hot water use.

Storage electric boiler

Includes a built-in or separate cylinder. It can store hot water overnight, which may help with certain electricity tariffs.

Suited to homes with higher hot water demand.

Dry core storage boiler

Heats internal bricks overnight and releases the stored heat into a water tank. Works with Economy 7 tariffs.

Less common but useful where running costs need to be controlled.

Electric CPSU

A high-capacity storage unit that delivers very fast hot water.

Usually used in commercial settings or large homes with multiple bathrooms.

Solar compatible electric boiler

Contains an immersion heater that can be paired with solar PV or solar thermal. This can reduce running costs in suitable homes.

Advantages of electric combi boilers

Electric combi boilers offer several benefits that make them appealing to particular types of homes.

Simple installation

They do not need a flue or gas pipework. This often means faster installation and fewer structural changes.

High efficiency

Because there are no waste gases, almost all the power used becomes heat. This keeps performance consistent across the year.

Low emissions at point of use

Electric boilers do not burn fossil fuels and produce no emissions during operation. This makes them suitable for lower-carbon households.

Low maintenance

There is no annual gas safety check and no risk of flue blockages or gas leaks.

Internal components are simpler and usually require less servicing.

Safe and quiet

With no combustion, there is no risk of carbon monoxide. They also run quietly because they contain fewer moving parts.

Flexible placement

Many electric combis are compact enough to fit in kitchen cupboards or utility spaces.

Disadvantages and limits to consider

Electric combis are not ideal for every home. Understanding the limitations is an important part of EEAT-level guidance.

Higher running costs

Electricity costs more per kWh than gas. Even with strong efficiency, many homes will spend more to produce the same level of heat.

Limited hot water output

Most electric combis cannot match the flow rates of mid or high-output gas combis.

Homes with two or more bathrooms may experience slow or inconsistent hot water.

Power supply limits

Some properties do not have the electrical capacity to support higher-output electric boilers.

An electrician may need to upgrade the consumer unit or main fuse.

Reliance on electricity

A power cut means no heating or hot water until supply returns.

Who electric combi boilers suit best

An electric combi boiler is most suitable for:

• Flats and smaller homes with one bathroom

• Rural or remote homes without a gas supply

• Homes with good insulation and low heat demand

• Households focused on low-emission solutions

• Properties where installing a flue is difficult

Homes with several bathrooms, very high hot water demand or poor insulation may be better suited to a different heating system.

What to look for when choosing an electric combi boiler

These simple checks help narrow the options.

Property size

Most electric combis are designed for smaller homes. Check the recommended property size in the manufacturer’s guide.

Hot water demand

If your home uses several taps at once, choose a model with a built-in cylinder or consider a storage boiler instead of a combi.

Output rating

Electric boilers usually range from 6 to 15 kW for standard homes. Higher outputs may need a stronger electrical supply.

Tariff considerations

Homes on Economy 7 or similar tariffs may benefit from storage boilers rather than combis.

Installation space

Check dimensions carefully to ensure the unit will fit inside a cupboard or utility area.

Keeping running costs manageable

Although electric boilers can be more expensive to run, costs can be controlled by:

• Using a smart thermostat for better scheduling

• Improving insulation and draught proofing

• Running appliances at off-peak times where tariffs allow

• Using solar panels if the boiler is compatible

Best electric combi boiler conclusion

Electric boilers are becoming more common across the UK and are a helpful option in certain homes.

If you are comparing electric units against modern gas boilers, you can read our guide to the best combi boilers 2025 for a wider overview of current options.

iHeat can offer guidance when you are ready to explore suitable heating systems and understand which type is best for your property.

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