ChiliTec ST35

3 500 W, and what that covers

ChiliTec states a maximum load of 230 V, 16 A — 3 500 W — for the ST35, printed on the unit and repeated across every market listing we checked. That number is the one to hold against the nameplate wattage of whatever you plan to plug into it, not the other way round. Among the space heaters reviewed on this site, the highest wattage is 2 000 W, on the De’Longhi Radia S, the De’Longhi HCM2030, and the Rowenta SO2212F0’s Turbo setting — each of those draws about 8.7 A, comfortably inside the ST35’s 16 A rating. The Dreo Atom 316 (1 500 W, about 6.5 A) and the Könighaus P-Serie 1000 W, the Bestherm ALBA, the Noirot Radiaflo, and the Alpina CHYO2 at their lower settings (1 000 W, about 4.3 A) sit even further under it. None of that changes if you plug in a heater rated above 3 500 W, or a second appliance at the same time — the rating is for the load the thermostat switches, not a target to approach.

What “1 °C steps” and “±1 °C” actually control

The dial sets a target between +5 °C and +30 °C in whole-degree steps, and ChiliTec states a ±1 °C switching threshold around that point — the relay clicks the load on when the reading drops a degree below the setpoint, and off when it climbs a degree above it. The listing also states a 10-second measurement interval with a deliberately delayed reading, which ChiliTec describes as a way to stop the thermostat reacting to a brief draft rather than a genuine temperature change. None of these figures are marketing copy in the sense of an unverifiable claim — they’re the switching logic the device is built around, printed the same way in every market listing we checked.

Internal sensor, not a probe

The ST35 measures at the plug itself, using a sensor built into the housing rather than an external probe on a cable. That’s a meaningful difference from a thermostat with a remote sensor: the air right at a socket, especially one a heater is plugged into, runs warmer than the middle of a room once the heater has been cycling for a while. In practice that means the room can settle a degree or two below the number on the dial. It’s not a fault specific to this unit — the McPower TCU-330 reviewed elsewhere in this hub uses the same internal-sensor approach — but it’s worth knowing before you assume the dial reading is the room reading.

Where we found it in stock

We checked Amazon.de (DE), Amazon.fr (FR), Amazon.it (IT), Amazon.es (ES), Amazon.co.uk (GB), and Amazon.com (US). ASIN B01MZFKWS5 carried a live offer on DE, FR, IT, and ES, at prices from about 22 € (DE) to around 28 € (ES). The same ASIN has a catalog page on Amazon UK but no live seller or price at the time we checked, and we found no ASIN at all under this EAN on Amazon US — so we’re not listing either as available.