Floating Temperature sensor?

Does anyone know of a floating water temp sensor? Or a sensor that could remain submerged and provide water temps? I’m looking to monitor my hot tub temp via ST. The wireless display and sensor I’m using (not connected to anything) just died.

Could I drop a Peq water sensor and leave it submerged? Anyone tried that?


The only thing that comes to mind is Qubino ZMNHEA1 probe which connects to a module, but I don’t see anything for a US version of it, only a European Z-Wave version.

EDIT: It appears there is an Insteon one available that might be able to be hacked around using an Insteon hub if you have or can get one cheaply enough. I know some people are using Insteon controlled lights with ST using the Insteon hub.

While it may take a little calibration, the sensor of your choice in a small ziplock bag should work just fine.


And you should be able to add some weights to submerge it to the level you want.
That will definitely be the easiest way to go about it.

Thats a reasonable idea, I can drop the Peq water sensor in a water tight bag and leave it the filter area. Should read the water temp pretty accurately. Its easy enough to try since i already own a couple the Peq sensors.

My buddy used his food vacuum sealer to make a waterproof holder it sealed real well but he put silicon seal where the wire comes out. IMPORTANT YOU MUST MAKE A SMALL HOLE FOR THE PROBE OTHERWISE YOU WILL MELT THE WIRE. If you use the roll material seal one end make the hole for the probe then seal the other end. Once sealed then silicon the small opening for the probe.

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I have done this with the ST Multi sensor. Our hub is indoor and we have twin 6yos. So I what to know when the tub opens. Currently the sensor is in a dime bag attached to the under side of the hot tub cover. in the fold between the two pieces of the cover. magnet on one side and sensor on the other. These are attached using 3M wet applications command strips. it works, but is still temperamental. Problems: the Temp is like 6-8% low (corrected in the UI but not optimal) and the bag shifts a little and the bag is not a tight fit. Potential solutions: embed the sensor in hot-glue copper or aluminum heat sink that dangles to the water. I have done the hot glue trick with other electronics and can set it up to replace the battery quickly, I don’t want to kill the sensor or the signal. I already have 2 walls, 20 feet and 3 inches of foam. Question: any feel on the broadcast ability when I add the hot glue?

I ended up purchasing an ST water sensor with temp. I grabbed my iphone water proof case and threw the sensor in there. At first I tried submerging it in the filter area of the tub but got no transmission from it. So then I just let it float on top of the water and its reading 97 degrees when I know the water is 100 degrees. Thats close enough for me to monitor if the tub looses power.

Still, someone should manufacture something like this that can be submerged and completely out of site. I don’t know if this is impractical but it would be a nice device for hot tubs, swimming pools, the lake behind your house, etc.

I know this thread is old, but did anybody end up finding anything that would fit the bill short of the ziplock bag? I ran across the qubino sensor on ebay but I have no idea if I need anything else to connect it so st, and coding is completely beyond me. I guess im really looking for plug and play submerged, floating temp sensor.

Check out this thread. I’m planning to do this soon…

For what its worth, i used the water proof camera bag and a regular sensor as I stated above. I wrote a simple program that alerts me via text when the temperature drops below a certain temperature. Its been running since this thread started and works great for me. If someone creates a real submersible sensor I’ll be interested.


So essentially any motion/door/etc sensor that has temp should work in a bag and floated in the area? Is there anything that would work without having to write a program? That’s all completely over my head.

Hi Ben, it will work without a program. Just put in the cell phone bag and throw it in the water. The sensor will correctly (accurate enough for me) return the temperature. I just wanted the program to alert me if the temperature dropped below a threshold. There’s no way to do that without a program of some sort to monitor the temp against the threshold.


Alright, thanks!

not a good idea… the bag will be sucked into either the intake or the filters

To each their own, my scenario is a hot tub so there’s no intake or any way the thermostat, floating on top of the water, can get into anything.

I could really use something that can be submerged also. I would like to monitor my aquarium temperature so I can get notifications if my chiller is not working.

Fibaro 857934005119 Modern Door/Window Sensor and DS18B20 Temperature Sensor Digital Temp Probe Waterproof

There are lots of threads here on this very setup. Start here:

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