Sonoff smart thermostatic head discounted to 799 CZK. Customers give it 4.7 out of 5

The heating season is starting, and with it, the annual tug-of-war over the radiator dial. It’s unbearable in the bedroom, cold in the study, and the bathroom is heated even when you’ve long been at work. A smart head solves this with a schedule for each room separately, and the SONOFF Zigbee Thermostatic Radiator Valve now costs 799 CZK instead of 999 CZK with code ALZADNY20.

Quick summary:
✅ Makes sense if you already have a Zigbee gateway or Home Assistant at home and want to heat each room separately according to a schedule.
⚠️ Consider that without a Zigbee gateway, the head will not connect to your phone and can only be controlled manually on the display.
💡 For 799 CZK, you get a head with open window detection, which owners praise mainly for its quiet operation and easy pairing.

Cheaper than Aqara and with much better ratings

A few days ago, we wrote about a discount on the Aqara W600 head, which cost 952 CZK with a code, but only had 2.9 out of 5 among Alza customers. Sonoff is the opposite. With code ALZADNY20, you save 200 CZK, or 20%, and the rating remains at 4.7 out of 5.

Moreover, a decent sample stands behind that number. 33 customers rated the head, 91% of whom recommend it, and Alza records over 2,000 units sold with a complaint rate of 1.15%. Aqara, however, has an advantage in one thing: it supports Thread and Matter, while Sonoff only communicates via Zigbee.

The head always belongs to one specific radiator. Anyone who wants to smartly control an entire apartment will need more of them, and the discount is most noticeable when buying multiple units.

It won’t communicate with your phone without a Zigbee gateway

The head communicates via Zigbee 3.0 and requires a Zigbee gateway to pair with the application. According to reviews, owners successfully operate it with Home Assistant via Zigbee2MQTT and with a Tasmota hub. One of them points out that without a gateway, it only works manually and cannot be added to the eWeLink application.

Once the head is paired, you can set the temperature from your phone, plan time schedules and scenes for individual rooms, and even control it by voice via Google Assistant or Alexa. A backlit display with manual controls remains directly on the radiator, so you can adjust the temperature even without your mobile phone.

Among its features, the open window detection is noteworthy, which, according to the manufacturer, turns off heating during ventilation and turns it back on after the window is closed. There’s also frost protection and a child lock. Sonoff also promises lower heating costs. However, how much you actually save depends mainly on how economically you heat today.

Before you order it, check the valve

Alza states compatibility with RA, RAV, RAVL, and M28 type valves; the necessary adapters are included in the package. One customer adds that the head fit an M30 threaded valve even without a reducer. During installation, calibration can also be set according to the valve depth, which another owner praises.

Dimensions must also be considered. According to one reviewer, the head is slightly longer than the original manual head in a panel building. This didn’t bother him, but if the radiator is tucked behind a cabinet or close to the bed, it’s better to measure the space. Power is provided by three AA batteries, which, according to another owner, lasted almost the entire heating season.

Can it only open and close? Owners dispute

In 13 written reviews, quiet operation and easy pairing with Home Assistant are repeatedly mentioned. People also praise the number of reducers in the package and the option to rotate the display. One customer, on the other hand, described the motor as noisy, so more sensitive sleepers might have a different impression than the majority.

Most of the debate revolves around regulation. Some older reviews complain that the head only fully opens or fully closes the valve, and therefore the temperature may not be precise. However, another owner counters that in Home Assistant, they see an adjustable degree of valve opening and closing, and the most recent review from October reports that with the latest firmware, smoother regulation works. Therefore, it is worth updating the head before installation.

Minor criticisms are directed at the display, whose backlight, according to one reviewer, cannot be adjusted, so it might be disturbing in the bedroom at night. Another customer describes a creaking nut when tightening. Overall, however, satisfied owners prevail, as indicated by 26 five-star ratings out of 33.

Who Sonoff won’t make happy

If you don’t have a Zigbee gateway at home and don’t want to get one, the discount won’t help much, as you’ll have to add the gateway’s price to the head’s cost. Those building a smart home on Matter should rather look for a head with Thread.

Disappointment may also come to those who want fine-tuned regulation right out of the box without tweaking in Home Assistant, or those who sleep in a bedroom sensitive to every little light. And for a radiator where there are only a few centimeters between the valve and furniture, a measuring tape will decide earlier than the price.

Almost a clear choice for Home Assistant owners

I would primarily consider the Sonoff Zigbee head for a household where a Zigbee network is already running and only smart heating is missing. For 799 CZK with code ALZADNY20, you get a quiet head with schedules, open window detection, and a rating that is not a given for smart heads, as the mentioned Aqara shows. Those starting from scratch and not wanting to deal with a gateway will rather opt for a head with Matter, which they can connect directly to Google Home or Apple Home.

Do you control heating room by room with smart heads, or do you still turn the dial manually?