How it works
What’s actually inside a radTherm electric radiator
Not all electric radiators work the same way. Here’s what makes a radTherm radiator different from a plug-in oil-filled heater, and how the patented heat-retention core inside every one warms your room.
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- Patented heat-retention core
- Made in Germany
- 30-year guarantee
- Thermostat or app control
The technology
A patented heat-retention core, not a heating element in a box
Inside every radTherm radiator, chrome-nickel steel heating conductors are moulded into a patented heat-retention core. The core soaks up heat as the radiator runs and keeps releasing it after the power switches off, while the built-in digital thermostat holds the room at the temperature you set.
That’s the same idea as a storage heater, applied the other way round. A storage heater charges its bricks overnight and then can’t control how the heat comes back out. A radTherm core warms up in minutes, whenever you switch it on, and the thermostat decides when it needs topping up.
The result: once a room is up to temperature, a radiator draws power for around 12 to 15 minutes an hour, depending on the building and the weather outside, and keeps warming the room for up to 45 minutes after the thermostat cuts the power.
Independently tested
Warm from floor to ceiling
Ever wondered why your toes feel cold while the heating’s on full? With many heaters the warm air sits above your head. The fluted design of a radTherm radiator spreads heat through the whole room instead.
Six times the surface area
Individually spot-welded fins give each radiator around six times the effective surface of a flat panel the same size, so warmth spreads by radiation and natural convection.
Within 0.5°C, floor to ceiling
Building services researchers BSRIA measured a radiator set to 21°C with seven sensors from 30cm to 2.2m high. The temperature varied by just 0.5°C.
Warm in minutes
Unlike a storage heater, there’s no overnight charge to wait for. Switch a room on and it starts warming straight away.
A fair comparison
How is this different from an oil-filled radiator?
Oil-filled radiators, the portable plug-in type sold in most DIY and electrical shops, heat oil inside sealed columns. They’re inexpensive and portable, but they’re built for occasional, single-room use: slow to heat, quick to cool once switched off, and not designed or warranted for permanent whole-home heating.
radTherm radiators are wall-mounted, professionally installed and built to run every day for decades, which is why they carry a 30-year manufacturer’s guarantee.
30 years manufacturer’s guarantee on a radTherm radiator
1–2 years typical warranty on a portable oil-filled heater
Built to last
German engineering, not just a label
radTherm radiators are made to order in Germany to tight manufacturing tolerances, which is part of why the core and casing hold up to decades of daily use. It’s also why every radiator carries the same 30-year manufacturer’s guarantee, whatever its size, colour or finish.
Control
Set it once, or control it from anywhere
Every radTherm radiator has its own digital thermostat built in, so it works precisely straight out of the box, with no separate app required. If you’d like to control rooms or schedules remotely, the radiators can also be run from an app on your phone or tablet.
Common questions
How electric radiators work: what people ask us
The questions we’re asked most often by people researching how radTherm radiators work.
How do electric radiators actually work?
Inside a radTherm radiator, heating conductors are moulded into a patented heat-retention core, controlled by a built-in digital thermostat. The core warms up in minutes and keeps releasing heat after the power switches off, while the thermostat holds your set temperature, rather than heating constantly or releasing heat on a fixed schedule like a storage heater.
What’s the difference between radTherm and an oil-filled radiator?
Oil-filled radiators are portable plug-in heaters made for occasional single-room use: inexpensive, but not built or warranted for permanent whole-home heating. radTherm radiators are professionally wall-mounted and built to run daily for decades, which is why they carry a 30-year manufacturer’s guarantee.
What’s the difference between a heat-retention core and a storage heater?
Both hold heat, but the similarity ends there. A storage heater charges its bricks overnight on a fixed tariff and releases that heat slowly over the next day, with little control. A radTherm core heats up in minutes, any time you switch it on, and the digital thermostat decides how much heat the room needs: you don’t have to commit in advance.
Are radTherm radiators actually German-made?
Yes. radTherm radiators are made to order in Germany, which is part of why every radiator carries the same 30-year guarantee regardless of size or finish.
Do I need a smart thermostat to control radTherm radiators?
No. Every radTherm radiator has its own digital thermostat built in and works precisely without any hub or app. App control is there if you’d like it; it’s an option, not a requirement.
How long does a radTherm radiator take to heat up?
Minutes, not hours. Unlike a storage heater, which has to charge overnight first, a radTherm radiator starts warming the room as soon as you switch it on.
Keep reading
More about our radiators
See it for yourself
Get the brochure, or book a free survey
The brochure has full technical specifications for every radTherm size and finish. Or book a free survey and Neil will show you how it works in your own home.