Looking for a thermostat

Hardware
1

Hi,
I have a special thermostat in my garage to control in floor radiant heating (glycol). The thermostat has 2 temperature probe 1. the normal one for the room, 2. in the concrete slab.

Do anyone know of a thermostat model that I could use to have the same control and also could be used with home assistant ? locally controlled would be preferred (not cloud based).

right now, this is the model that was installed :
https://www.homedepot.com/p/tekmar-Radiant-519-Digital-Non-Programmable-1-Stage-Heat-Thermostat-with-Slab-Sensor-079-TEK519/206393869

thank you for any hints on this… I’ve been looking on the web without much success :slight_smile:

2

@Rigor_M

Did you ever swap your Tekmar 519 out for something else? I’ve been wanting to do something with mine too, it’s just too basic. I see Tekmar has a wireless model but requires using Tekmar site or app.

I might switch to it just for the “auto off based on outdoor temperature” feature…

3

@cybergrimes

Nope, still have it on the wall in my garage. My boiler is mecanical so basic on/off cycles. The thing that stumps me is the second 10k thermistor in the floor and basic rules that ir needs to follow.

For now, i only have a dht22 connected to a esp8266 to give me the temp/humidity. Its pretty close to what the teckar is showing on the screen.

4

Any news on this question?

I’m also trying to find a ‘smart’ thermostat that also accepts the sensor input, but no luck so far.
The closest I got was some Nest forum saying it ignores any slab temperature – i.e. it does not need/use it as an input.

That makes me wonder: apart from controlling the maximum slab temperature (which is clearly a good feature!), what does the slab temperature sensor help the thermostat achieve? What you really care about at the end of the day is the room temperature, right?

5

Ive since bought a new house.

But i did find a thermostat that would of worked.

Sinope does a floor thermostat with a second probe. Its low voltage and can be used for glycol. They have a zigbee (my choice) or wifi.

I actually have that model in my new house’s garage but connectes ro a 30A load relay from stelpro for a 5000W ceiling heater.

But that thermostat has pins for a second probe. Sold seperate.

I have it connected to HA via zigbee2mqtt.

Works great. You can see the specs on the website.

Hope this helps

BTW, they also do wired floor heating thermostats up to 3600W ans you can add power modules if you have multiple zones.

6

Great find, thanks! Zigbee is also my preference.

Looking at the installation manual, it supports my 10kΩ floor sensor. :+1: Now I just need to figure out if it can control the air temperature while limiting the floor temperature.
EDIT: it does: “A mode (default): Regulation of ambient temperature with the possibility to limit floor temperature through an external temperature sensor”

BTW, how is it so difficult to find this stuff? Whenever I searched for some sort of ‘smart’ thermostat for hydronic floor heating, I either got a standard smart thermostat, with no floor temperature features, or a high-voltage electrical floor heating thermostat, not suitable for low-voltage settings. Go figure.