Domoticz

I ordered a WT0122 Pool Thermometer, and I know there are identical looking types that either work with RFlink or do not work with it. So, my question might be more of the noob variety than an RFLink -related question, but the question is:

If I have the right device, should it just appear on the list of devices that RFLink sees, as soon as I put the batteries in?

Domoticz shows the following device which I suspect to be this thermometer, or could it be some neighbor's device?
50 RFLink 0000 0 Pool TempHum Temp + Humidity WTGR800 0.0 C, 0 % - - [Set Unused] [Rename Device] [Log] 2017-03-24 04:30:32

I added this as a device, but it's showing in red in the "temperature" devices list, and not seeming to receive any info from there.

So, I guess the core question is: If I had the correct device, would it just show up in there, or would I have to do some setting up first?

Yes, it should show up.
If not, we can check by looking at a debug log..

Thank you for your fast response. I entered the debug mode, and I took out the batteries of the sensor part of the WT0122, and then put them back in, and this is what appeared to the debug log:
20;BF;DEBUG;Pulses=58;Pulses(uSec)=0,900,390,1860,390,1860,390,1860,390,1860,39;
20;C0;DEBUG;Pulses=25;Pulses(uSec)=330,900,390,870,390,1860,390,1860,390,1860,3;
20;C1;DEBUG;Pulses=23;Pulses(uSec)=420,1770,360,840,360,1770,360,1770,360,1860,;
20;C2;DEBUG;Pulses=29;Pulses(uSec)=450,1860,390,900,390,1860,390,900,390,900,36;
20;C3;DEBUG;Pulses=33;Pulses(uSec)=0,900,390,900,390,900,390,870,390,1860,390,9;
20;C4;DEBUG;Pulses=41;Pulses(uSec)=120,1860,360,930,390,900,390,1860,390,900,39;
20;C5;DEBUG;Pulses=100;Pulses(uSec)=2400,4860,1740,990,570,690,1740,990,570,690;

There was a bit of delay before the last line (20;C5;...) appeared, so I am not 100% certain it isn't some other device.

When I repeat the exercise (take out batteries for a few secs and put them back in) a moment later, this is what I get:
20;01;DEBUG;Pulses=100;Pulses(uSec)=2400,4860,1740,990,570,690,1740,960,570,690;
20;02;WT0122;ID=0075;TEMP=00fb;
20;03;DEBUG;Pulses=100;Pulses(uSec)=2400,4860,1740,990,570,690,1740,990,570,690;
20;04;WT0122;ID=0075;TEMP=00fb;

To my amateur eye, maybe the latter would seem more like the right stuff, considering there's the word "WT0122" and "TEMP=.." in there..

More log:
20;43;DEBUG;Pulses=100;Pulses(uSec)=2400,4860,1740,960,570,690,1770,960,600,660;
20;44;WT0122;ID=0075;TEMP=00f6;

And it's currently showing 24.6C on the pool thermometer's LCD and hex 00f6=246, I am pretty confident that the above is the pool thermometer's log.

Hmm, now I checked the devices list again, and looks like it appearing on the device list now:
58 RFLink 0075 117 WT0122 Temp LaCrosse TX3 23.9 C - - [Add Device] [Rename Device] [Log] 2017-03-24 21:41:23

Could it be that the difference is that I moved it just a few meters to the living room? If it won't work from the dining room where it was for first tests, it definitely won't work from the pool area. Are there any repeaters available for RFLink, or should I try to find some kind of a slave device solution besides the domoticz+RFlink that I have at my main entrance...

This is strange... The device has not been seen by Domoticz since 22:09 yesterday evening, the time when I last posted. I left it at the exact same physical location as it was when the temp was received, but it hasn't been received since. First I was wondering if it's that it only sends the temperature information when it changes, but now that I've been watching the device and the temperature changing on the screen, there's nothing on Domoticz even though the temperature changes.

...any ideas?

I might have solved the mystery. Looking at the behavior and the data received by domoticz, it looks like the temperature sender unit has some sort of a tolerance for the change of temperature before it does send a message. If I make the sender unit temperature a bit warmer, I seem to be receiving the temperature, and when it cools down back to room temperature, the temperature appears at regular intervals until it is room temperature, then it might be hours without new data appearing.

Would be great if someone else that owns a WT0122 device could confirm this is the way it works?

I too bought one of these and experienced the same problem, but now...

...I have a Secure SRT-321 Z-Wave thermostat in a ziplock bag inside an ice cream container floating in my spa.
Works perfectly!!

Nice idea with a thermostat in a ziplock in the pool

But i still bought the same poolthermometer (13,48 € with remote lcd display). It was much cheaper than your ziplock idea (88,99 € conrad.de).

Is there already a solution for displaying the pool temperature with the pool thermometer?