How the Heatomi PTC Heater Works

The PTC ceramic principle

PTC stands for positive temperature coefficient. A PTC ceramic is a material whose electrical resistance goes up as it gets hotter. When you switch the heater on, a lot of current flows through the cold ceramic and it warms quickly. As it warms, its resistance climbs, the current drops and the temperature levels off.

The result is an element that, in effect, limits itself. That is why PTC ceramic is widely used in small fan heaters, and it is one reason the technology is seen as relatively robust. It does not make a heater immune to misuse, so the usual safety habits still apply. See our safety guide.

In practice, that means a PTC heater warms up quickly and then holds a steady working temperature, rather than glowing red like an old-fashioned bar fire. It is still a mains appliance drawing real power, so treat it with the same respect as any other heater.

The HeatCore element and fan

The seller calls the Heatomi's ceramic element HeatCore™. The image shows a cutaway: the ceramic element sits at the centre of the unit, with a fan that draws in room air, moves it across the warm element and sends it back out as warm air.

This is a convection-style fan heater. It warms the air in the room and the area directly in front of the unit more than it warms walls and furniture. In a small space, you can feel the difference fairly soon after switching on. In a large or draughty room, a compact heater like this will struggle, and we do not know its power rating to say more.

Because it relies on a fan, expect some fan noise. The seller does not give a noise figure, so we cannot say how loud it is.

Modes, temperature and timer

• Two heat modes. The seller lists two modes, which is typically a lower and a higher output setting. Use the lower one when the room is only slightly cool.
• Adjustable temperature. You can set a target temperature rather than just running it flat out.
• Timer up to 90 minutes. Set it so the heater turns itself off after a fixed period, for example while you work or get ready for bed.

A timer is a convenience, not a safety system. Never rely on it to make leaving a heater unattended acceptable.

Controls and shut-off features

The seller lists touch controls on the unit and a remote control, so you can change modes or the timer from across the room. There is no app and no installation: it plugs into a standard wall socket.

For protection, the seller lists tip-over shut-off (the heater switches off if knocked over) and overheat shut-off (it switches off if it gets too hot). The body is described as flame-retardant ABS. These are sensible features, but we have not tested them, so check the manual and product label when it arrives.

Using it sensibly: place it on a hard, flat surface a good distance from furniture, aim it towards where you sit, pick the lower mode first, and use the timer so it does not run longer than you intend. If the room is still cold after a reasonable time, the heater may simply be too small for the space.

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