A Simple Guide to Electric Radiators, Panel Heaters, Storage Heaters and Electric Boilers
Electric heating is used in millions of UK homes.
For some households, it provides heating for the entire property. In others, electricity supplements another heating system or warms individual rooms.
However, the term electric heating covers several very different technologies.
An electric radiator does not work in the same way as a storage heater. Meanwhile, an electric boiler behaves differently again.
Heat pumps also use electricity, but they work on a fundamentally different principle from conventional electric heaters.
Understanding these differences is important because they affect:
- How quickly your home heats
- How you control the heating
- When electricity is used
- Which electricity tariff may suit you
- How much the heating may cost to run
So, before thinking about efficiency or tariffs, it helps to understand what type of electric heating you actually have.
How Does Electric Heating Work?
Most conventional electric heaters use electrical resistance to produce heat.
Electricity passes through a heating element, which becomes hot.
That heat is then transferred into the room.
In simple terms:
Electricity → heating element → heat
This basic principle is used in many different types of heater.
However, the way that heat reaches the room can vary considerably.
Direct Electric Heating
Direct electric heating produces heat when electricity is being used.
Switch the heater on and it begins producing heat.
Switch it off and the electrical heating stops.
Examples include:
- Electric radiators
- Panel heaters
- Convector heaters
- Fan heaters
- Oil-filled electric radiators
- Infrared heaters
- Some electric underfloor heating
These systems are relatively simple.
However, because they use electricity at the time you want the heat, the electricity price at that time can have a major effect on running costs.
Electric Radiators
Electric radiators are designed to heat individual rooms without requiring a wet central-heating system.
They may be:
- Wall-mounted
- Freestanding
- Oil-filled
- Dry-element
- Fluid-filled
- Smart-controlled
Although designs vary, they all ultimately use electricity to provide heat.
Many modern electric radiators include controls such as:
- Thermostats
- Timers
- Weekly schedules
- Open-window detection
- Smartphone apps
- Individual room programming
Therefore, they can offer considerable control over where and when heating is used.
Are Electric Radiators 100% Efficient?
You will sometimes see electric resistance heaters described as 100% efficient.
At the point of use, essentially all the electricity consumed by a conventional resistance heater ultimately becomes heat within the property.
However, this statement can be misleading if it is interpreted as meaning:
“Electric radiators are therefore the cheapest or most efficient way to heat a home.”
That does not necessarily follow.
Running cost depends heavily on the price of electricity.
Furthermore, other technologies such as heat pumps can deliver substantially more useful heat to a property than the electrical energy they consume because they move heat rather than simply creating it through electrical resistance.
Therefore, efficiency percentages need context.
Panel Heaters
Panel heaters are usually wall-mounted electric heaters designed to warm a room relatively quickly.
Many heat the surrounding air, creating convection currents that distribute warmth through the room.
They can be useful where:
- Heating is needed for limited periods
- Individual room control is important
- Installing wet central heating would be impractical
- A room needs occasional additional heat
However, like other direct electric heaters, they consume electricity while actively producing heat.
Therefore, controls and electricity prices matter.
Convector Heaters
Convector heaters primarily warm the air.
Cooler air enters the heater, becomes warmer and rises.
As that warm air moves through the room, cooler air takes its place and the process continues.
Convector heaters can warm a room relatively quickly.
However, once switched off, they may retain relatively little heat compared with heavier radiators or storage systems.
Therefore, they can be useful for quick heating but may not suit every situation as a primary whole-home system.
Fan Heaters
A fan heater combines an electrical heating element with a fan.
The element becomes hot, while the fan pushes heated air into the room.
As a result, fan heaters can provide warmth very quickly.
However, they are generally better suited to short-term or occasional heating than continuously heating an entire home.
They can also have relatively high power ratings.
For example, a 2 kW fan heater operating at full power for one hour would use approximately:
2 kW × 1 hour = 2 kWh
The actual cost would then depend on your electricity unit rate.
Oil-Filled Electric Radiators
Oil-filled radiators contain a sealed thermal fluid.
Electricity heats an internal element, which then heats the fluid and metal body of the radiator.
The radiator subsequently releases that heat into the room.
Because the radiator contains thermal mass, it can remain warm for some time after the electrical element switches off.
However, this does not create free energy.
The heat released afterwards is energy that was previously supplied by electricity and stored temporarily in the radiator.
Therefore, claims that oil-filled radiators somehow produce significantly cheaper heat simply because they remain warm after switching off should be treated carefully.
Infrared Heating
Infrared heaters work differently from conventional heaters that primarily warm the surrounding air.
They emit infrared radiation that can warm people and surfaces directly.
This can create a different sensation of warmth and may be useful in particular situations.
For example, infrared heating may work well where you want to heat:
- A particular occupied area
- A workspace
- A room used intermittently
- People or surfaces without first heating a large volume of air
However, infrared heating still uses electricity.
Therefore, it does not make the cost of each kWh of electricity disappear.
Its potential advantage comes from how and where the heat is delivered, rather than creating more energy than it consumes.
Electric Underfloor Heating
Electric underfloor heating uses electrical heating cables or mats installed beneath the floor.
As they heat, warmth is distributed across the floor surface.
This can provide comfortable, even heat.
It is commonly used in rooms such as:
- Bathrooms
- Kitchens
- Extensions
However, electric underfloor heating can involve a substantial electrical load if it heats large areas for long periods.
Therefore, insulation, controls and operating schedules are particularly important.
A warm floor can feel pleasant, but leaving it heating unnecessarily can become expensive.
Electric Boilers
An electric boiler performs a similar role to a gas boiler but uses electricity rather than burning gas.
It heats water that can then circulate through:
- Radiators
- Underfloor heating
- Other wet heating systems
Depending on the arrangement, it may also contribute to domestic hot-water production.
Therefore, a property can have familiar radiators and central-heating pipes without having a gas boiler.
The main difference is the source of heat.
Gas boiler:
Gas → combustion → heats water
Electric boiler:
Electricity → electrical heating element → heats water
Is an Electric Boiler the Same as a Heat Pump?
No.
This is an important distinction.
An electric boiler normally converts electrical energy directly into heat.
A heat pump, however, uses electricity to move heat from one place to another.
For example, an air-source heat pump extracts heat from the outside air and transfers it into the home.
As a result, a heat pump can provide more heat energy to the property than the electrical energy used to operate the system.
Therefore:
Electric boiler = creates heat using electrical resistance
Heat pump = uses electricity to move existing heat
Both use electricity, but they are fundamentally different technologies.
We explain heat pumps separately within Renewables.
What Are Storage Heaters?
Storage heaters are another form of electric heating, but they work differently from direct electric heaters.
Instead of using most of their electricity at the same time that you want the room heated, traditional storage heaters are designed to store heat for later.
They usually contain materials capable of retaining substantial amounts of thermal energy.
During a designated charging period, electricity heats the internal storage material.
The heater then releases that stored heat gradually.
In simple terms:
Electricity → heat stored inside heater → heat released later
This can be particularly useful when the electricity used for charging is cheaper than electricity at other times.
Storage Heating and Off-Peak Electricity
Storage heaters have traditionally been associated with tariffs such as Economy 7.
These tariffs provide cheaper electricity during specified off-peak periods, often overnight.
The heater charges during the cheaper period and releases the stored heat later.
Therefore, storage heating is not simply about the heater itself.
The electricity tariff and heating controls are part of the system.
If a storage heater is charged using expensive electricity or configured poorly, its running costs may be very different from those of a correctly controlled system using an appropriate tariff.
We will cover this properly in:
Storage Heaters Explained →
Modern Storage Heaters Are Different
Older storage heaters could be difficult to control.
For example, they might release too much heat early in the day and have little remaining by evening.
Modern high-heat-retention storage heaters can provide much better control.
Depending on the model, they may include:
- Electronic thermostats
- Timers
- Fans
- Automatic charging controls
- Programmable heating schedules
- Better insulation
- Additional boost functions
Therefore, experiences with very old storage heaters do not necessarily reflect how modern systems operate.
What Is an Electric Boost Heater?
Some storage heaters include an additional direct-acting electric heating element.
This can provide extra heat when the stored energy is insufficient.
However, the boost heater may use electricity at the rate applying when the boost is operating.
If that is during an expensive peak period, the heat can cost considerably more than heat stored using cheaper off-peak electricity.
Therefore, boost heating is useful, but understanding the tariff is important.
Portable Electric Heaters
Portable heaters can be useful for occasional or supplementary heating.
Examples include:
- Fan heaters
- Oil-filled radiators
- Portable convectors
- Infrared heaters
Their main advantage is flexibility.
For example, if you are working in one room for a short period, heating only that space may sometimes make more sense than heating an entire property.
However, portable heaters need to be used safely.
Keep them away from combustible materials, follow the manufacturer’s instructions and never cover a heater that is not designed for that purpose.
Is One Type of Plug-In Heater Much Cheaper Than Another?
This is an area where marketing claims can become confusing.
Suppose two conventional resistance heaters each use 1 kWh of electricity.
Broadly speaking, both will ultimately release approximately that electrical energy as heat into the property.
Therefore, an expensive plug-in heater cannot magically turn the same 1 kWh of electricity into several times as much resistance heat.
However, one heater may still be more suitable for the job.
For example:
- A fan heater may provide quick local warmth
- An oil-filled radiator may release heat more gradually
- An infrared heater may warm an occupied area directly
- A panel heater may integrate better with room controls
So, compare heaters based on control, comfort and suitability, rather than expecting fundamentally different electricity costs from heaters using the same amount of electrical energy.
Why Controls Matter So Much
With direct electric heating, good controls can make a major difference.
Because rooms can often be controlled individually, you may be able to avoid heating areas that are not being used.
For example:
Living room
Warm during the evening.
Bedroom
Warm around bedtime and morning.
Home office
Warm during working hours.
Spare room
Lower temperature when unoccupied.
This can be one of the strengths of electric heating.
Instead of treating the whole property as one heating zone, you may be able to match heat more closely to how rooms are actually used.
Thermostats Do Not Change the Price of Electricity
A thermostat helps control how much heating is required.
It does not change the electricity unit rate.
When the room reaches the selected temperature, the heater can reduce or stop its electrical consumption.
Therefore, sensible thermostat settings can reduce unnecessary heating.
However, turning a thermostat to maximum does not normally make the room warm faster.
Instead, it can simply cause the heater to continue operating until the room becomes warmer than necessary.
Timers and Schedules
Timers can prevent electric heating from operating when it is not needed.
Therefore, consider when each room is actually occupied.
For example, there may be little benefit in heating a home office throughout the evening if nobody uses it after 5pm.
Likewise, a bedroom may not need to remain at the same temperature throughout the day.
Modern controls can make these schedules much easier to manage.
Smart Electric Heating
Some modern electric-heating systems can be controlled through smartphone apps.
Depending on the system, you may be able to:
- Set room temperatures
- Create schedules
- Turn heating on or off remotely
- Control rooms separately
- Monitor heating activity
- Adjust settings while away
This can make electric heating more convenient.
However, smart controls do not create cheap energy.
Their benefit comes from helping you avoid heating unnecessarily and control the system more accurately.
Electric Heating and Smart Tariffs
Time-of-use electricity tariffs can create opportunities for some electrically heated homes.
For example, electricity may be cheaper during certain overnight or daytime periods.
However, whether you can benefit depends heavily on the type of heating.
A storage heater can store thermal energy for later.
A home battery may store electricity for later.
However, a simple direct electric radiator generally needs electricity when it is producing heat.
Therefore, a cheap overnight tariff is not automatically useful if most of your direct heating is needed during expensive evening periods.
Always consider the heating technology and tariff together.
How Much Does Electric Heating Cost?
A simple calculation can help.
Suppose a heater is rated at 2 kW.
If it operates continuously at full power for one hour:
2 kW × 1 hour = 2 kWh
If electricity costs 25p per kWh:
2 kWh × 25p = 50p
However, a thermostatically controlled heater may not operate continuously at full power once the room reaches the desired temperature.
Therefore, the power rating tells you the maximum rate of electricity consumption while actively heating, not necessarily what the heater will consume every hour it is switched on.
Don’t Judge a Heater Only by Its Power Rating
A 2 kW heater uses electricity twice as quickly as a 1 kW heater while both operate continuously at full output.
However, the more powerful heater may warm the room faster and then switch off through its thermostat.
Therefore, simply choosing the lowest-powered heater does not guarantee the lowest overall energy consumption.
The important factors include:
- Room heat loss
- Desired temperature
- Heating duration
- Controls
- Heater location
- Electricity price
Ultimately, the room needs enough heat to replace the heat it is losing.
Why Insulation Matters
Electric heating cannot compensate cheaply for a building that loses heat very quickly.
If heat escapes through poorly insulated walls, roofs, floors, windows or draughts, the heating system must continually replace it.
Therefore, improving the building can reduce the amount of energy needed regardless of the heating technology.
This is why heating and energy efficiency should be considered together.
Electric Heating in Flats
Electric heating is common in flats because it can avoid the need for:
- Gas supplies
- Flues
- Central boiler systems
- Extensive heating pipework
Individual room control can also be convenient.
However, electricity costs and tariff choice become particularly important where electric heating provides all of the property’s space heating and hot water.
Therefore, if you live in an all-electric property, understanding your meter, tariff, heating controls and hot-water system is especially important.
Electric Heating and Hot Water Are Separate Questions
An electrically heated home may use one technology for space heating and another for hot water.
For example:
Storage heaters + immersion-heated cylinder
or:
Electric radiators + immersion-heated cylinder
or:
Electric boiler + hot-water cylinder
Therefore, don’t assume that identifying the room heaters automatically tells you how your hot water is produced.
Learn how your hot-water system works →
Direct Electric Heating vs Storage Heating
The simplest distinction is:
Direct Electric Heating
Uses electricity when you want heat.
Examples include electric radiators, panel heaters and fan heaters.
Storage Heating
Uses electricity to store heat for later.
This can allow the system to take advantage of cheaper electricity periods where an appropriate tariff is available.
Neither approach is automatically right for every household.
The better option depends on the property, occupancy pattern, controls and tariff.
Direct Electric Heating vs a Heat Pump
There is an even more important distinction.
Resistance Heating
Uses electrical energy directly to create heat.
Heat Pump
Uses electrical energy to move heat from outside the property into the home.
As a result, heat pumps can potentially provide several units of heat for each unit of electricity consumed under suitable conditions.
That is fundamentally different from ordinary resistance heating.
Therefore, when comparing electric heating systems, don’t group heat pumps and electric radiators together simply because both use electricity.
Common Electric-Heating Mistakes
Several mistakes can increase running costs unnecessarily.
These include:
- Heating unused rooms
- Leaving manual heaters operating unnecessarily
- Setting thermostats higher than required
- Using expensive boost heating without understanding the tariff
- Charging storage heaters at inappropriate times
- Assuming every cheap-rate tariff suits every electric-heating system
- Ignoring draughts and insulation
- Believing that one resistance heater can somehow produce dramatically cheaper heat than another while consuming the same amount of electricity
Understanding the system is often the first step towards avoiding these problems.
Which Electric Heating System Do I Have?
Look around the property and identify the equipment.
Ask:
- Do I have wall-mounted electric radiators?
- Do the heaters have input and output controls?
- Are they large, heavy storage heaters?
- Do they charge overnight?
- Is there an electric boiler?
- Do I have wet radiators connected by pipes?
- Is there electric underfloor heating?
- Do I have an immersion-heated hot-water cylinder?
- Does my electricity tariff have cheaper periods?
These clues can help identify how the property is heated.
If you are unsure, find the manufacturer and model numbers of the equipment before changing settings.
Know Your Electricity Tariff
For electrically heated homes, the tariff can be just as important as the heater.
Check:
- Your electricity unit rate
- Standing charge
- Whether you have more than one unit rate
- The times when different rates apply
- Whether heating circuits are separately controlled
- Whether you have Economy 7 or another time-of-use tariff
Then compare those details with when your heating actually uses electricity.
A tariff designed around overnight storage heating may not necessarily suit a household relying mainly on direct electric heating during the evening.
Likewise, changing tariff without understanding how the heating is wired and controlled can produce unexpected results.
Use Your Smart Meter to Understand Heating
If you have a smart meter, your in-home display or phone app can help you understand electricity consumption.
For example, you may be able to see:
- Consumption increasing when heating starts
- Daily electricity patterns
- Differences between mild and cold days
- Overnight electricity use
- Changes after adjusting heating schedules
However, remember that your smart meter normally measures the home’s total electricity consumption.
It does not necessarily identify each heater individually.
Use the information to understand patterns rather than assuming every increase has one cause.
Learn more about smart meters →
Safety Matters
Electric heaters are powerful electrical appliances.
Therefore:
- Follow the manufacturer’s instructions
- Keep portable heaters away from combustible materials
- Do not cover heaters unless specifically designed for that purpose
- Do not use damaged cables or plugs
- Avoid unsuitable extension leads
- Do not attempt internal electrical repairs unless competent and appropriately qualified
- Never obstruct heaters in a way that could cause overheating
If a heater repeatedly trips an electrical protective device, becomes damaged, smells unusually hot or behaves abnormally, stop using it and have the problem investigated.
In Short
Electric heating is not one single technology.
A home might use:
Electric radiators → direct room heating
Panel or convector heaters → direct air heating
Fan heaters → rapid local heating
Oil-filled radiators → direct heating with some thermal storage
Infrared heaters → direct radiant heating
Electric underfloor heating → heat distributed through the floor
Electric boilers → electrically heated water circulated through a wet heating system
Storage heaters → electricity stored as heat for later use
Meanwhile, heat pumps are different again because they use electricity to move heat rather than simply producing it through electrical resistance.
Therefore, before deciding whether electric heating is expensive, efficient or suitable, identify:
What heating system do you have?
When does it use electricity?
How is it controlled?
What tariff are you paying?
Once you understand those four things, electric heating becomes much easier to manage.
Energility
Understand More. Spend Less. Live Better.