Electrically heating the humble home can be a bit of a minefield, and not all radiators are made equal. Here then, I look at the in’s, out’s pros & cons to help you select the right kind of rad for your room.
In this article, I’ll look at several electric heating technologies and where they’re best employed because, if you get it wrong, you may end up with something which either doesn’t do the business effectively, or it costs an arm and a leg to install or to run. With the exception of infrared panels, of which I’ll talk more later, all electric radiators employ an element that turns electricity into heat. It’s what that element is warming up that makes all the difference in purchase and running costs.
Generally, electric heating is a very clean and efficient technology as 100% of the electricity consumed is turned into heat with no waste products. Sometimes a heater may employ additional whistles and bells such as a lighting effect, but a traditional resistive element as used in most of these products will convert Watts of electricity directly into equivalent Watts of heat with no losses. Beware of rogue online ads which claim to have some kind of new super efficient heating technology; nobody has invented anything more efficient than 100%!
Most electric radiators come in different size ranges with larger models being both thirstier on the power but better able to heat a space more efficiently. Manufacturer data will give a floor area that any given model ought to cover. Of course, whatever heating method you employ, you should ensure your home is as insulated as possible so that the air you're paying to warm up isn't quickly lost.
In 2018, an EU directive named LOT 20 came into force in an attempt to improve the energy efficiency of heating appliances. An unfortunate upshot of this is that modern electric radiators have computerised controls over the basic dials employed by older models, and they require 24/7 power for these interfaces to operate. Often, replacing an old radiator for a new one means something a lot more complicated to operate, plus these new controls have pushed up the purchase price significantly from where things were back in 2017.
Let’s start with the midrange models; describing how they operate will better illustrate how both the higher and lower-end technologies work.
The oil or dry-filled radiator.
For some reason that I’ve never quite fathomed out, these are quite cheap if you buy them on wheels as a portable radiator, however if you want one that’s to be hung on the wall then the cost suddenly spirals upwards. These radiators have a mid-range bulk, weight and price tag. Traditional offerings had basic mechanical switches or perhaps a timer dial, but modern models are more likely to have a computerised interface and even, heaven forfend, smartphone support via a bloody app!
On a filled radiator, the heating element warms up a storage medium usually formed of a liquid oil or a dry clay. It takes power when the element is on, however when the target room temperature is reached and the thermostat shuts off the power, the radiator continues to provide warmth from the heated storage medium without running up the electric bill. Eventually, the temperature of this medium will have decayed as its heat passes to the air in the room, in which case the radiator will once again draw power if the thermostat senses the room temperature is starting to drop below the set point. You can think of this type of radiator like a kettle; that too uses electricity to heat up a medium, water in this case, but after the kettle clicks off, that water remains hot for some time afterwards.
Most of these models of radiator are passive and will silently heat the room using convection, where natural movement sees cold air pulled in at the bottom to be warmed before rising from the top of the radiator. It then circulates to the far side of the room as the warm air passes over the ceiling before cooling and falling again. Examples may be sourced with a fan assisted mode to quickly heat a room space from cold actively rather than passively.
Electric heated towel rails tend to be of this type with quite small heating elements (maybe about 300W or so). These take some time to warm up the liquid inside them and some time to cool down when power is shut off. This ‘time shift’ should be borne in mind when setting timers - programming it to turn on half an hour before your regular showering time will ensure it’s up to temperature for when you fling your towel across it.
Pros
Uses electricity more efficiently than an ordinary panel radiator as it continues to radiate heat after the power shuts off.
Cheaper to run and more effective than an ordinary panel radiator.
Portable (plug-in) models are available.
Quick to start warming a room, especially if fan assisted.
Cons
Expensive to buy.
Heavier than a basic panel radiator.
Bulky on the wall.
Some appliances such as towel radiators don’t heat up instantly and require some thought to go into the ‘time shift’ when setting up for optimal use.
Panel radiators.
As I’ve already touched upon ordinary panel radiators, let’s look at these next as they’re very similar to the filled rads but simply lack the oil or clay storage medium. This makes them cheap and slimline, but very binary in operation: they’re taking power all the time they’re on, using no power and putting out no heat when off. This means that if you want to heat a room, you turn the rad on, set the temperature and it will guzzle electricity until it reaches that temperature. After that, it will stop putting out any heat at all until the room temperature falls, at which point the thermostat will click it back on again. It’s another quiet and passive solution that uses convection to warm the air in a room. Fan heaters are the same thing, but they use a fan to actively blow the heat from the element in order to warm a space quickly.
Pros
Cheap to buy.
Slimline profile on the wall.
Portable (plug-in) models are available with or without fan assistance.
Quick to start warming a room, especially if fan assisted.
Cons
Requires power all the time it’s radiating heat, so it’s the most expensive to run.
Storage heating.
Storage heaters are a complicated beast, so I’ll start with the basics. Like the filled radiators described earlier, storage heaters have a medium called a ‘core’ which is made up of heavy thermal blocks that tightly sandwich the heating elements. Unlike the filled radiators which warm up relatively quickly, it takes time for a storage heater to heat its core. That’s generally okay though as the idea behind them is that they click on in the small hours when electrical demand is off-peak, so by the time you climb out of bed with your hangover, the core is nice and hot. As you wake up and the off-peak power clicks off, the heater continues to radiate heat from its core for several hours without using the more expensive peak-rate electricity.
If you’re on a two-rate tariff such as Economy 7 or Economy 10, then your off-peak power will be at a much lower price, so the benefit of a storage heater is that it ‘charges’ up when electricity is cheap overnight and then it dissipates its heat throughout the day when you really need it. Economy 7 gives you seven hours of cheap rate overnight and this time-shifts across different nights and different locales to prevent a surge on the grid whereby all heaters would otherwise click on simultaneously. Economy 10 allows for ‘boost’ periods in the day so that a storage heaters can top-up their core ready for the evening demand. Sometimes, especially in a living room, you might have a storage heater that has both an off-peak and a peak supply allowing an override function so that it can be used at any time of the day as desired. It should be said that you don't get something for nothing, and that lower cost per kWh you pay off-peak sees a larger price per kWh during peak times. Economy tariffs, if available, are only cost effective if you use a lot of power at night through the use of several storage heaters, EV charging etc.
Where things get complicated is how the tariff switching works. Older sites will have a physical time-switch either built into the meter or sitting adjacent to it that physically clonks the heater(s) on at night. Newer sites may supply power 24/7 to the heater with the tariff switching simply on the billing. Here, a local controller built into each heater, or located by it, will dictate when the heater is to operate.
Older heaters are very basic – one dial to set how much power you want to go in, which you would turn down on warmer nights, and another dial which opens a mechanical flap if you want more heat to dissipate out of the core during a cold day. In many cases there is no kind of override, so if you want to warm a room and the heater wasn’t switched on the night before, or if the core has already leached out all its heat, then you’re bang out of luck until the next day mate!
To comply with LOT 20, modern storage heaters all have computerised controls which mean they must have 24/hour power even if the heating itself is externally controlled and doesn’t click on until the middle of the night. This makes retrofitting old-for-new tricky as most old models tended not to have a peak supply available. Also, the modern controls tend to be non-intuitive and difficult to navigate making operation complicated for those who are used to the simple dials of their old model.
Storage heaters tend to be found in homes that have no gas supply. Older models are often ugly affairs that were beige to begin with and have discoloured over time.
Pros
When used correctly, cheap to run which helps to offset the purchase cost long term.
Continues to radiate heat without power long after an oil or dry-fill radiator would have cooled.
Cons
Very expensive to buy and to install.
Very heavy and bulky on the wall.
Older models were simple to control, new models are not.
Replacement of older models may require a new peak supply service to be installed.
Requires a two-rate tariff which may not be available for your installation.
Infrared radiator panels.
The previous heaters described above all use convection – they draw in cold air and output warm air which rises and circulates throughout the room, sometimes with the aid of fan assistance. Because they’re heating the air in the room, their effectiveness may be impaired by draughts and open windows or doors. Infrared heaters work differently. Instead of heating the air, they emit energy as infrared waves which heats people or objects directly in their path. Infrared energy is not visible to the human eye, although some IR heaters, especially potable or exterior models, use elements which give a visible bright red glow as they operate, sometimes as an aesthetic simply to provide a visible warming glow. You’ll commonly find this technology in pub beer gardens or above exterior café/restaurant tables or smoking areas where heating the outside air itself would be impractical.
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| Interior wall mounted IR radiator | Exterior IR heaters |
Wall or ceiling mounted IR panel heaters tend not to emit visible light and usually have the appearance of a white slimline panel.
Pros
Not susceptible to draughts or irregular air movement.
Can cost less to run than a standard panel radiator.
Cheap to buy.
Portable (plug-in) models are available.
Good for exterior patio heating as it warms people and objects rather than air.
Very light and svelte in build.
Cons
Like a panel radiator, they have no storage medium and burn through electricity all the time they’re operating.
Will only heat objects in direct line-of-sight; does not heat the air in a room.
Requires suitable wall or ceiling space as mounting is critical to ensure it will heat the target objects.
May have to be mounted at height which places it in the eyeline along with any services such as cables and controls.
Downflow heaters.
A downflow heater is a basic fan heater which I’ve already touched upon. These are usually mounted high on the wall with a pullcord switch control. A fan blows over a heating element to exhaust warm air downwards and at an angle to quickly warm up a small space such as a bathroom. They take a lot of power but tend to only be used for a short time to take the chill off. Previously, such rooms may have employed a ceiling bar-heater which is less efficient, more dangerous to the touch and which have now largely fallen out of favour.
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| Downflow heaters tend to have a local pullcord control. | Still available, but rarely seen these days, are the old bar heaters/lights which downflow heaters have largely replaced in bathrooms. |
Pros
Cheap to buy.
Portable (plug-in) models are available.
Active heating by blowing out hot air makes it an effective way to quickly warm a small space.
When used properly, a safer and more efficient solution to the ceiling bar-heaters of old.
Cons
Expensive to run.
Like a panel radiator, they have no storage medium and require power all the time they’re operating.
Underfloor heating.
Underfloor solutions may be wet systems where hot water is piped around a floor space, or electric where a resistive heat-mat is used. It’s the latter I’ll talk of here, although the general principles are common to both. If you have a tiled or laminate floor, then this is a good way to take off the chill underfoot which itself serves to make you feel warmer and more comfortable. The heating element is relatively large as it covers a whole floorspace which, even in a small room, is larger than the element space available in a wall radiator. This means it can operate at a lower temperature and at a lower power. It also means the whole floor radiates heat upwards into the room to help heat the entire space more evenly, whereas a wall radiator has a hot spot focused at one end of the room only.
Underfloor heat mats need to be carefully planned to ensure they’re only placed in open spaces in a room. If covered by furniture, both heat and energy will be wasted, and it can create a point where the mat cannot dissipate its heat correctly which may result in premature failure. Similarly, failing to place the element where needed may create noticeable cold spots. A design that fits one room may be no good if you choose to then rearrange that room and move large furniture such as a sofa or bed to a different position.
Often, electric underfloor heating should be considered as an additional comfort rather than the primary source of room heating. Used in conjunction with a wood burner or another source of heat radiation it can very much add to your comfort, but if relied upon as a primary heating method then it may disappoint. It’s also very ineffective under floor coverings such as carpets and rugs.
Underfloor controllers usually use a floor temperature probe and a room air-temperature sensor to operate. Rogue installers often omit the floor probe which can lead to problems later.
Laminate heat mats tend to sit under the laminate boards which means they can be replaced fairly easily, but installations under tiles are often embedded in a levelling compound or tile adhesive which means they need to be wholly broken out and replaced should they fail.
Pros
Taking the chill off a laminate, tile or solid floor can very much add to your comfort.
Has a lower power and a larger, more even, heating area than a wall radiator.
Long life reliability (there’s not much to go wrong so long as there’s no flooding or puncture damage).
Cons.
Limits your floor coverings and the room layout after fitting.
Electric versions are best used with a second means of space heating.
Has to be fitted properly to ensure correct operation.
Difficult to repair or replace if it fails, as the floor covering has to come up.
Expensive to install and will require the floor to be prepared with the correct levelling and insulation before it is laid.
The above solutions are not the be-all-and-end-all, but this is a quick and dirty guide to the types of electrical heating options that are out there, and I’ve put it together following recent enquiries whereby people have scoffed at the price of replacing storage heaters because they’re looking at the price of panel radiators. Electric heaters are not all the same, and there’s a good reason why an £800 storage heater isn’t the same as an £120 panel rad. The better and more efficient a technology is long term, the more expensive it is to buy.
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