Moes ZSS-HM-CO-A Zigbee carbon monoxide (CO) detector alarm

The wireless link or network the device uses. Wi-Fi connects straight to the router; Zigbee, Thread and Bluetooth Mesh work through a hub or gateway.

Whether the device needs a separate hub, gateway or coordinator to work in a smart home. If so, it is sold separately unless stated otherwise.

How the device connects to Home Assistant: a built-in integration, a Zigbee coordinator, Matter or the maker’s cloud integration.

The maker’s app used to set up and control the device.

The coordinator's maximum radio output. Higher power gives a steadier link to distant devices, but range in a home depends more on walls and the number of routers in the network.

Which hazards the device notices. Most models react only to carbon monoxide; combined models also detect smoke, heat or natural gas.

The sensing element of the device. An electrochemical sensor is used in most household CO alarms and draws little power, so it can run on batteries for years; a semiconductor sensor needs constant heating, so such devices are usually mains-powered.

The lowest carbon monoxide concentration at which the device raises an alarm, in ppm (parts per million). At low concentrations the standard has the alarm sound after a delay rather than at once, so the response time is given in the note.

After how many years, according to the maker, the device must be replaced: a CO sensor loses sensitivity over time. Whether this counts from first use or from the production date is given in the note.

The standard the maker states the device was tested to. EN 50291-1 is the European standard for household CO alarms: it sets the concentration and the time within which the alarm sounds — at 50 ppm after 60–90 minutes, at 100 ppm after 10–40 minutes, at 300 ppm within 3 minutes. EN 50291-2 does the same for motorhomes and boats.

The housing colour of this model. Other colours in the same series are separate products.

Whether the device shows the current CO concentration as a number. Without a display, gas is reported only by the siren, indicator and app; a display also shows a rise in concentration that has not yet reached the alarm level.

Volume of the built-in siren as stated by the maker; the distance it was measured at is given in the note. The same decibel figure at 3 m means a louder source than at 1 m; each extra 10 dB sounds roughly twice as loud.

Whether the device signals with a sound, an indicator or in the app that the sensor is faulty or has reached the end of its service life. EN 50291-1 requires such a signal; without it a faulty device looks the same as a working one.

Where the device gets its power: 230 V mains, an adapter, USB, batteries or a built-in battery.

Which cells it takes and how many. A built-in rechargeable battery is stated in the value.

Typical life on one set of batteries or one charge, per the maker. Frequent triggers, cold and a weak signal shorten it.

Whether the device warns in advance that the battery needs replacing — with a short beep, an indicator or an app message. A device with a dead battery no longer warns about carbon monoxide.

The supply voltage (and current, if stated) as the maker gives it. It must match your mains or adapter.

Whether batteries come in the box or have to be bought separately.

The warranty period the maker states. Confirm warranty terms in Moldova with the seller.

How and where it is installed: in a wall box, on a wall or ceiling, on a DIN rail, on a table or in a socket.

The air temperature range the device is rated for. The lower limit matters outdoors, on balconies and in unheated rooms.

The rated relative humidity range, non-condensing.