Electric Heating in the UK: Storage Heaters, Heat Pumps, Underfloor Heating & Running Costs.

Electric heating has changed dramatically over the last decade. Older night storage heaters are gradually being replaced with smart electric radiators, high heat retention storage heaters, heat pumps and intelligent heating controls.

With rising gas prices, the push for lower carbon homes and the growth of solar panels and battery storage, many homeowners are asking whether electric heating is now a realistic and affordable option?

This guide explains:

• How different electric heating systems work
• Typical running costs
• Slimline vs older storage heaters
• Heat pumps as electric heating
• Electric underfloor heating mats
• Economy 7 tariffs
• Lot 20 regulations
• Wiring and electrical requirements
• Installer qualifications and regulations
• Smart controls and zoning
• Using electric heating with solar and batteries

How Electric Heating Works.

Unlike gas or oil systems, electric heating converts electricity directly into heat.

Most electric heating systems are close to 100% efficient at the point of use, meaning nearly all electricity consumed becomes heat. The main difference between systems is how the heat is stored, distributed and controlled.

Electric heating systems generally fall into four categories:

1. Direct acting electric heating.
2. Storage heating.
3. Heat pumps.
4. Electric underfloor heating.

Direct Acting Electric Heating

Direct acting systems produce heat instantly when switched on.

Examples include:

• Panel heaters.
• Electric radiators.
• Infrared heaters.
• Fan heaters.
• Oil-filled radiators.

These are simple to install and ideal for:

• Well insulated homes.
• Occasional use rooms.
• Extensions.
• Loft conversions.
• Home offices.

The downside is running cost. Direct electric heating uses peak-rate electricity unless paired with smart tariffs, batteries or solar generation.

Typical Running Costs

As a rough guide:

• 1kW heater running for 1 hour = 1kWh of electricity.
• At 27p per kWh, that costs around 27p per hour.
• A 2kW heater could cost around 54p per hour at full output.

Modern smart controls can significantly reduce costs by .preventing overheating and allowing zoning.

Old Storage Heaters.

Older storage heaters were designed around Economy 7 tariffs.

They contain bricks that heat overnight using cheaper off-peak electricity, then slowly release heat during the day.

Traditional units usually had:

• Manual input and output controls.
• Basic thermostats.
• Poor insulation.
• Little control over heat release.

This often caused problems:

• Homes overheating during the day.
• Rooms becoming cold in the evening.
• High daytime boost usage.
• Poor efficiency compared with modern systems.

Many older systems are still installed in flats and electrically heated homes across the UK.

Running Costs of Older Storage Heaters.

Older systems can still work reasonably well if:

• The home is well insulated.
• The heater is correctly sized.
• Economy 7 is configured properly.
• Occupants are home during the day.

However, they can become expensive if:

• Heat is released too early.
• The property has poor insulation.
• The boost heater runs on peak-rate electricity.
• The Economy 7 meter or tariff is incorrectly configured.

Slimline and High Heat Retention Storage Heaters.

Modern storage heaters are significantly better than older units.

Slimline and high heat retention (HHR) storage heaters:

• Retain heat for longer.
• Use better insulation.
• Include digital thermostats.
• Feature programmable controls.
• Learn occupancy patterns.
• Reduce wasted heat release.

Modern HHR systems are designed to comply with Lot 20 regulations and can work well with smart tariffs.

Benefits include:

• Better evening comfort
• Lower running costs
• Improved controllability
• Better compatibility with renewable electricity

They are particularly suitable for:

• Flats without gas.
• Apartments.
• Off-gas homes.
• Retrofit properties where heat pumps are unsuitable.

Economy 7 and Storage Heaters.

Economy 7 provides cheaper electricity for around seven off-peak hours overnight.(hence economy 7)

Storage heaters charge during these periods and release heat throughout the following day.

A properly configured Economy 7 setup typically requires:

• Dual-rate electricity meter
• Off-peak consumer unit or dedicated circuits
• Correct timing configuration
• Separate peak and off-peak supplies on some systems

Some modern storage heaters require two separate supply cables:

• Peak supply
• Off-peak supply

This is common with advanced Lot 20 compliant systems.

Lot 20 compliant refers to a set of EU/UK Eco design regulations (under the Energy Efficiency Directive 2015/1188) requiring local space heaters, including electric radiators, panel heaters, and underfloor heating to meet minimum energy efficiency standards. More info below.

Heat Pumps as Electric Heating.

Heat pumps are also electric heating systems.

Unlike direct electric heating, they do not create heat directly. Instead, they move heat from outside air or the ground into the home.

Air source heat pumps are now the most common type in UK homes.

Why Heat Pumps Are Different

A heat pump can typically deliver:

• 3kW to 5kW of heat for every 1kW of electricity used

This makes them far more efficient than direct electric heating.

Best Conditions for Heat Pumps

Heat pumps work best with:

• Good insulation
• Low temperature heating systems
• Larger radiators
• Underfloor heating
• Airtight homes

Poorly insulated homes may still require expensive upgrades before a heat pump performs efficiently.

Running Costs

Although electricity is expensive compared with gas, the efficiency of heat pumps can offset this.

Running costs depend heavily on:

• Flow temperatures.
• Property insulation.
• Heating controls.
• Occupancy patterns.
• Electricity tariffs.

Smart tariffs, batteries and solar PV can improve economics significantly.

Electric Underfloor Heating Mats.

Electric underfloor heating mats are increasingly popular in:

• Bathrooms.
• Kitchens.
• Extensions.
• Renovations.
• Small rooms.

The system uses electric heating cables or mats installed beneath the floor finish.

The floor surface becomes a low temperature radiator, gently heating the room.

Types of Electric Underfloor Heating

Heating Mats.

Pre-spaced cables attached to mesh.

Best for:

• Regular room shapes.
• Tiled floors.
• Faster installation.

Loose Cable Systems.

Flexible cable layouts for:

• Irregular rooms.
• Complex floor plans.
• Custom spacing.

Foil Heating Systems.

Typically installed beneath:

• Laminate.
• Engineered wood.
• Floating floors.

Power Outputs

Typical outputs are:

• 100W/m² for background heating
• 150W/m² to 200W/m² for primary heating

Running Costs

Electric underfloor heating can be expensive if used as the main heat source in poorly insulated homes.

However, in smaller spaces such as bathrooms, it can provide excellent comfort with relatively manageable running costs.

Good insulation beneath the heating mats is essential.

Without insulation boards, a large amount of heat can be lost downward into the subfloor.

Heating Controls for Electric Heating.

Controls are one of the biggest factors affecting running costs.

Modern systems can include:

• Smart thermostats.
• Zonal controls.
• App-based scheduling.
• Open window detection.
• Adaptive start.
• Occupancy learning.
• Weather compensation.
• Load balancing.

Good controls help electric heating compete more effectively with gas systems.

Smart Tariffs and Load Shifting

Modern controls can automatically:

• Heat during cheaper tariff periods
• Store heat during low-cost electricity windows
• Prioritise solar generation
• Charge batteries during off-peak periods

This is becoming increasingly important as flexible electricity tariffs expand.

Lot 20 Regulations.

Lot 20 regulations were introduced to improve electric heating efficiency standards.

Affected products include:

• Storage heaters.
• Electric radiators.
• Panel heaters.
• Underfloor heating.
• Infrared heaters.
• Electric fires.

The regulations require heaters to achieve minimum efficiency standards and include improved control functionality.

Common Lot 20 features include:

• Electronic thermostats.
• 24/7 programming.
• Open window detection.
• Adaptive start controls.
• Digital timers.

Modern compliant systems are significantly more efficient than older manually controlled heaters.

Heat pumps are generally treated separately.

Wiring Requirements and Electrical Loads.

Electric heating can place substantial demand on a property’s electrical system.

Correct cable sizing and circuit design are critical.

Typical Electrical Loads.

Approximate loads include:

Heating Type	Typical Load
Panel heater	1kW–2kW
Storage heater	1.7kW–3.4kW
Electric radiator	500W–2kW
Underfloor heating	100W–200W/m²
Heat pump	Often 16A–40A depending on size

Common Circuit Requirements

Electric heating systems may require:

• Dedicated radial circuits.
• RCBO or RCD protection.
• Isolation switches.
• Separate off-peak circuits.
• Load calculations.
• Consumer unit upgrades.

Typical examples include:

• 16A radial circuits for smaller heaters.
• 20A radial circuits for underfloor systems.
• 32A supplies for larger heating zones.
• Dedicated heat pump supplies.

Cable sizes commonly include:

• 1.5mm²
• 2.5mm²
• 4mm²
• 6mm²

Actual requirements depend on:

• Installation method.
• Cable run length.
• Insulation around the cable.
• Total connected load.
• Diversity calculations.

Some Lot 20 storage heaters require both peak and off-peak supplies.

Installation Regulations.

Electric heating installations in the UK must comply with:

• BS 7671 Wiring Regulations.
• Part P Building Regulations.
• Manufacturer instructions.
• Local building control requirements.

Special locations such as bathrooms have additional requirements regarding:

• IP ratings.
• Zones.
• RCD protection.
• Isolation distances.

Underfloor heating installations may also require:

• Floor probes
• Thermal insulation boards
• Resistance testing
• Certification before covering

Qualifications Required to Install Electric Heating.

Electrical heating systems should be installed by suitably qualified professionals.

Depending on the work involved, this may include:

• Qualified electricians.
• NICEIC registered contractors.
• NAPIT registered installers.
• Heat pump engineers.
• MCS certified heat pump installers.

Heat pump installations linked to government grants such as the Boiler Upgrade Scheme usually require MCS certification.

Electrical work involving new circuits is generally notifiable under Part P.

Solar Panels, Batteries and Electric Heating.

One of the biggest advantages of electric heating is compatibility with renewable electricity.

Electric heating systems can work alongside:

• Solar PV.
• Home batteries.
• Smart tariffs.
• Vehicle-to-home systems.
• Time-of-use tariffs.

Using Solar with Electric Heating.

Solar panels can offset daytime electricity use from:

• Electric radiators.
• Heat pumps.
• Underfloor heating.
• Hot water immersion heaters.

However, solar generation is usually lower during winter when heating demand is highest.

This is why battery storage is increasingly important.

Batteries and Load Shifting.

Home batteries allow homeowners to:

• Store cheap overnight electricity
• Use stored electricity during peak-rate periods
• Reduce grid imports
• Improve solar self-consumption

Smart electric heating systems can coordinate with batteries and tariffs automatically.

This approach is becoming particularly effective with:

• Heat pumps
• High heat retention storage heaters
• Smart electric radiators

Is Electric Heating Worth It?

Electric heating can work extremely well in the right property.

The best outcomes usually depend on:

• Excellent insulation.
• Airtightness.
• Smart controls.
• Correct system sizing.
• Suitable tariffs.
• Renewable electricity integration.

For many homes, especially flats and off-gas properties, modern electric heating may now be a more realistic option than it was ten years ago.

However, poor insulation and badly controlled systems can still lead to very high running costs.

Before choosing any electric heating system, homeowners should consider:

• EPC improvements.
• Insulation upgrades.
• Ventilation requirements.
• Heat loss calculations.
• Tariff suitability.
• Future solar and battery integration.

Final Thoughts.

Electric heating is no longer limited to outdated night storage heaters.

Today’s systems include:

• Smart high heat retention storage heaters
• Efficient heat pumps
• Intelligent electric radiators
• Zoned underfloor heating
• Renewable-ready smart controls

When combined with insulation, solar PV and battery storage, electric heating can form part of a lower carbon and potentially lower cost home energy strategy.

The key is selecting the right system for the property, the occupancy pattern and the homeowner’s long-term plans.