Zen thermostat not always responding to Fan On command

[napalmcsr]

I see in the logs where it didn't work, then when I went in to command it, it then did work.
Red circle is working, blue is not.
Is there a way to sniff if the zigbee command was sent and the thermostat ignored or any other way to try to figure out why this happens sporadically?

[bertabcd1234]

I reported this problem a while back and was never able to find a resolution. I've since switched my thermostat for another (this problem didn't help but I had other oddities too). You can read more here and maybe something will work for you or you could add your findings:

Zen Thermostat fan mode won't go to "on"?

Does anyone else have a Zen Thermostat, and if so, have you noticed that manually setting the fan to "on" (via any method I've tried: Dashboard, the device's edit/admin page, etc.) does not work? It does get logged as if it's happening, but it doesn't happen. Setting the fan using the thermostat itself on the wall logs the same info but actually does cause it to happen. Changing to fanAuto via any method works as expected. This might be a more general thermostat problem, but I only have the Zen…

[napalmcsr]

Funny thing is I had the same issue with a pearl... I cycle my fan every hour if I haven't done a heat or cool, so I know it is an intermittent issue. I can go days without it happening.