I was just checking all my devices and I noticed I hadn't had any activity from the Heiman Combustible Gas Sensor (line powered, Zigbee) for a while. It appears to be completely dead. Has anyone else had this happen to this sensor?
Since it appears I may have to replace it - any suggestions for a better product?
My 2 are still chugging along. 2+ yrs
I would replace with same, assuming mfg hasn't made changes to the firmware as the chinese are so apt to do to break compatibility in a effort to sell "their" hubs.
sure its not the driver i recently updated the driver to check in every so often.. the older ones did not..
No, it shows no indication of power when plugged in. Test button does nothing, reset does nothing.
I believe it has expired.
So far so good... 
Bought from here with no issues. 
Of course they might be shipping something completely different now.
Same here, one of mine just died some months ago. Still looking for alternatives.
I apologize for resurrecting this thread BUT I want to add some longterm detail for these useful devices.
I bought a couple of these old * manufacturer: Heiman
In 2023 while slowly migrating to HE with the community-shared drivers, my #2of2 devices did pair and log tests and clearing, but the normally-green status light remains off. It could still be in an acclimatization phase, but I think it is actually automatically expired in its 5th year of operation. I don't recall if I found that documented specifically for this device, but it is a typical rating for solid-state combustible gas sensors that are common in cheaper gas detectors.
FYI #1of2 device that remains paired to Smartthings hub, it also logs tests and clearing, has ALSO stopped lighting the normally-green ring LED around the test button. Suggesting a built-in/hardware lifetime timer of 5years has expired.
In OP's case of LED off and all functions dead, that does sound like hardware failure.
Yes, in the manual pamphlets, the lifespan is 5 years. I am just saying in case someone else does a search trying to determine issues with the devices. My 2/2 just recently started intermittently beeping and blinking yellow after only 2 years of work. I knew of the 5 year lifespan but since I purchased mine from Aliexpress, I suspect that it may have already been "old" at the time. I emailed Heiman twice but got no response, not even an automated reply. So, hopefully an alternative is found for the next go-around.
As a related aside, I have a C-5 and after ordering a replacement Heiman Zigbee 3.0 and finding out I needed the aforementioned user driver, any chance the updated models have their system drivers to be compatible with the Heiman Zigbee 3.0?
Yep, mine died too. I don't know if it died by itself, or if it was a casualty from a recent nearby transformer failure (which killed all my battery backups and some bulbs). I have since installed a whole-home surge protector at the box. I wouldn't be surprised if the sensor failed by itself though.
I got a replacement Heiman "combustible" Zigbee 3.0, and it paired to Hubitat C-4 with no trouble, and I think no special driver.
Download the Hubitat app
