Does anyone know of a way to have Hubitat read the value of an in-floor temperature sensor, that does NOT involve purchasing a new thermostat? Could be Z-wave, Zigbee, or perhaps even something that Home Assistant could read (just getting started with that). If so, I'm all ears, and thanks in advance.
Here's the backstory: We built a new house this past year and put hydronic radiant heat in the concrete slab, to heat the garage (zone 1) and the separate entry foyer and downstairs bathroom (zone 2). In each zone, I put a Tekmar floor sensor down a 1/2" tube embedded in the concrete, and connected that to a Tekmar 561 wifi thermostat, designed for hydronic radiant heat. I can read the floor temperature just fine that way, but I really dislike these thermostats and one of them is already giving me problems (not turning on the dry contact to complete the circuit on the zone controller). I've already replaced that one with an old GoControl Z-wave Tstat I had in a previous building we owned, and it's working great for controlling that zone via air temperature. But I'd like to know the floor (slab) temperature as well, because that would allow me to create more sophisticated control over the heating if I could track that floor sensor temperature value.
BTW, I know I could just go buy a Honeywell T6 or some other Tstat that monitors both air and floor temperature, but I've already got everything I need to solve this, if I could just get the value of the floor sensor into Hubitat (or even Home Assistant, although I'm just starting to fiddle around with that). Thanks in advance for any help on this.
If you just need the temperature and no thermostat capabilities, a Fibaro Smart Implant (ZWave) and one of these will do it but the Fibaro is ~$50.
If you are going to start using Home Assistant and want to try ESPHome, you can use a $5 ESP32 with those same sensors. I think you could do it using Arduino instead of ESPHome and I think there is an Arduino community integration though I have never used it and know NOTHING about it.
I have one of each running in a chest freezer in garage that I turn off/on with smart plug to keep it at refrigerator temperatures.
I have to thank you for asking that question. Since I have both devices, I focus on the calculated average to control the plug and that is what I worry about. What I didn't notice until after responding to your thread was that the temperature coming from the Fibaro for the last 10 days hasn't changed. The dang thing stopped working. Time to troubleshoot!!!
First, hope you get things working again on your end. Good luck with it. As for my project, I have a Tekmar sensor installed now, which I believe is fairly standard (10K?) for the industry. The problem is how to read it, so I think I'll likely end up going down the HA / ESP route. Thanks for the suggestion.
Those old GoControl Tstats work well but they can only read and report in 1-degree increments. For hydronic in a concrete slab, by the time the temp drops a full degree and turns on the boiler and pump, it takes about 12 hours to bring the room temp back up to temp. The Tekmar Tstats are supposed to use both air temp and floor temp to control things, but they don't do a great job of it. They also won't integrate with either Hubitat or HA, require a cloud connection to monitor via phone, and their app is lousy. Not a fan!
Until I can measure floor temps, I think I might try using my Ecowitt system to monitor air temp at the 0.1 degree level, and a Zen 16 I have laying around to turn the zone controller on and off. That should allow me to turn on the boiler when the temp drops just a small amount and stays there for 10 minutes (maybe 0.3 deg below the setpoint) and turn it back off as it starts to rise. That will take a couple of hours or more, but should keep things in about a 1-degree range. Anyway, thanks for the suggestions!
