Water Pipe Temperature Sensor

I have a hot water circulating loop in my home that the plumbers did not insulate. Prohibitive propane costs keep me from even periodic circulation. The pump is currently controlled with a SmartThings Outlet and I use “Alexa” to call for hot water on demand. This command turns the pump on for 5 minutes only - just enough time to get water to the furthest fixture from the heater. This has improved my energy costs greatly but is somewhat inconvenient.

One solution is to simply add a larger capacity pump to improve delivery times and I will likely do this. However, I would also like to add a more efficient “modified” circulation mode.

My “modified circulation mode” would pulse the pump on/off based on the temperature at some desired point along the loop (likely the furthest fixture away from heater, but could be at any select fixture like kitchen sink, bath tub, etc.).

So, I need a Zwave or SmartThings device that would sense the outside temperature of the pipe or even perhaps have a probe that is mounted inside the pipe and communicate with the outlet connected to the pump.

Any ideas?


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Could you use one of the door/window sensors that have temp capability? Just zip ty to the pipe.

There are also some more sophisticated posts where someone adds an external thermistor.

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I am also interested in finding a solution… I have the same setup. So far I just had Webcore Tür on/off the hot water circulation before the usual schedule when I need it + via Alexa on demand.

I think the water pipes are too hot though for the plastic temp sensor. Also. Regular temp sensors measure „ambient“ temperature and not temperature at a specific contact point.

Will post if I have another idea…

I monitor the temperatures of my Heat Pump Freon Lines using DS18B20 temperature sensors like the following. I also monitor the Heat Exchanger Inlet and Outlet Air Temperatures. So, 4 DS18B20 sensors in all.

I have these tied into one of my NodeMCU ESP8266 microcontrollers running my ST_Anything Arduino software. I actually use just 1 digital pin for all four sensors, and each sensor is then created in ST as an independent child device. This allows each one to be used in any automation, like any other temperature sensor.


Might be able to use this? https://products.z-wavealliance.org/products/2990

Interesting… that’s very similar to the device I built. Mine even has a drip pan water sensor. The one I built also monitors the thermostat wiring to know if the heat pump is running, cool or heat mode, fan, and emergency heat.

Looks nice, but I was unable to find any seller or any other info.

RCS - link