Fibaro FGK-101 w/ probe | temperature variations normal?


(Jens Strauf) #1

Hello, I recently connected the Fibaro FGK-101 with a probe in my freezer. For whatever reason, I get quite some temperature variations that I doubt are real. Does anyone have experienced a similar issue? I understand there could be some due to the auto defrost function of the freezer but it seems a lot and very quick (see attached screenshot). It might also be related due to the low temperature but I would not expect this picture. Thank you in advance! Cheers, Jens


(John C) #2

Although I’m using a different (non-ST) solution, my small chest freezer temperature varies all over the place like that. Still well below freezing in the “safe” zone.

Which temperature probe did you choose? I’m probably going to switch to a similar solution with the Fibaro FGK-101, too.


(Jens Strauf) #3

Thanks for your response. I agree that it’s still in the safe zone and I created an alert once it goes above 20 F. It happens once in a while but drops the next minute again. Still confused as to why.

Anyway, this is the $6 probe I got: SUNKEE DS18B20 Temperature Sensor - Waterproof Digital Thermal Probe Sensor DS18B20DS18B20 Temperature Sensor - Waterproof Digital Thermal Probe Sensor DS18B20


(Eric) #4

that is the kind of twitchiness I would expect from naked bulb sensor - is that what you got? It’s not really too bad. Door leaks, air currents, and who knows what. In a lab environment that sensor might be immersed in a bottle of glycol to give it some thermal mass and reduce the noise.

I’ve been using a regular Smarthings (ST) door open/close sensor in the freezer - not twitchy. Now I pretty much only eat ice cream when the freezer is about 0, 'cuz I don’t like 20F.


(Cole Sumner) #5

I am trying to accomplish this exact same set up with the same sensor. Can you please share the handler you used? I am having a heck of a time finding one that will function properly. Are you also utilizing the closure contact or just using the wired sensor probe?

I have tried several handlers with no luck.


Is there a COTS Z Wave immersion temp sensor probe
(Eric) #6

device type/handler “Fibaro Door/Window Sensor ZW5 with Temperature”

it ain’t perfect - once I tamper with it, the tamper is set, then I try to clear it (not sure how) and it resets but immediately sets again, even when I keep squeezing the cover closed. The tamper indication is an eyesore but the other functions are unaffected.

Note the DS18B20 must be connected before power is made. Also external 4.7Kohm required - maybe you forgot it. Reading directions is a good thing, so I am told, often.

My magnetic contacts also work no problem.

You may have a counterfeit DS18B20. I don’t understand why manufacturing douchebags would choose to fake such a cheap sensor, but it’s a thing. I don’t have advice how to tell - just get some from a different source and try those.


(Eric) #7

it occurs to me that maybe your freezer (and fridge if combined) is mostly empty. If you put a bunch of ice or other mass then it will slow down.