Recently found these 433Mhz gas detectors on Aliexpress:
https://www.aliexpress.com/item/1005005032820588.html?spm=a2g0o.order_list.order_list_main.5.668c1802FgFo05
Didn’t even know they existed. 433 to get around the usual cloud reliance, but to my surprise they have wifi as well and are supported by the Tuya app. Also, you can add them as a detector if you have a 433/wifi alarm system (like the Digoo tuya system), that way it will call you if there is a gas leak.
But the best part is, they are actually working and sensitive (unlike Shelly or the Aqara sensor, i wouldn’t trust my life with those) and show the LEL on the front screen. I have it sitting a bit above and next to the gas hob, and it works very fast. Tasmota picks up the RF code on a Sonoff RF bridge right away, i trigger on both the tuya for picking up the PPM (i do above 1% PPM) and a binary mqtt sensor for if the gas alarm has been triggered (10% LEL on the tuya app), that way i’m not worried about internet not being there.
This way i have: internet, 433mhz for HA notifications, and linking it up to the alarm system i have GSM calls as well.
I am testing a few out, but so far this one has been the best and i’m thinking of getting a few more to cover other potential gas leak sources as well. I don’t know why but so far the cheap Tuya made ones are often very quick to react. It’s just that in the past i used the Wifi only ones, which are obviously relying on their cloud integration (if using in HA, they will still work and alarm without cloud (i hope/assume).
Also: they work with a usb cable as opposed to the Shelly plug (needs a socket, and is useless anyway) or the Aqara, which has their own proprietary plug).