In my house I have 3 circuits of floor heating elements, each is connected to single phase (230V) 16A fuse and on one of them I have Heatit Z-TRM3 connected via z-wave to my home assistant. Others are manually controlled dumb thermostats.
That thing works, but at least the particular one I got causes a lot of interference to the z-wave network, so I’m a bit hesistant to add any more of those.
Features I must have:
- Option for a floor temperature sensor. Each thermostat has separate pipe going to the floor and the floor sensor is easy enough to replace, but it is a must have option
- Air temperature sensor. 2/3 of the heating elements are in a concrete slab and that means that measured temperature of the slab very slowly affects the air temperature, so I need both. ESP32 or equivalent as a separate sensor might be a decent workaround, but I’d rather have both on a single unit.
- Obviously the 230V 16A capability as that’s what they’re wired on and even if I don’t have 3kW elements on the floor it’s what’s needed to meet the code
- Manual controls on the device itself. Should my raspberry pi running home assistant kick the bucket or some other major issue with the automations happens, I still need an option to control the device. And that’s a strict requirement, no bluetooth apps on the phone or anything, I must have manual buttons or some other way to control the thing without home assistant or any other smart device.
- And addition to previous one: No cloud requirement. Allowing the device to the internet for a setup is fine, but in the long run it must be happy in a isolated network without internet connectivity
For the communication I don’t really care. I currently have only wifi/z-wave as an option, but if there’s something on zigbee which ticks all the boxes I can invest in a usb-dongle or a hub.
Price is obviously a concern, but it’s hard to set any strict boundaries. I won’t throw a 1000€ for a thermostat, but anything even remotely reasonable goes.
What are your suggestions for a situation like this?
I have a similar setup with 3 different heating elements, each with it’s own different brand controller (who knows what the previous owner was thinking!).
I swapped one out a few years ago for a Heltun which seemed to meet my requirements and is designed for exactly that. It is the older discontinued model running on 500 series z-wave, their newer ones run on 700 series.
I had initially planned to replace all 3 with the same model assuming it was good - I haven’t (as yet) - it was a pretty new product and it was a bit buggy which made me hesitant. I have wood flooring on top of the concrete slab/ electric blanket in two areas and it’s advised to not heat the wood up too high as it causes shrinkage, unlike under ceramic tile, and sometimes it would not respect the max floor temperature setting. I went back and forth with their support about it and they were very helpful, giving me beta firmware to flash etc and I worked around it.
For the last couple of years it’s been mostly stable and behaving. For whatever reason, it no longer lets me directly set the target temperature in Home Assistant which it previously did - I may need to dig into that as it would be handy sometimes, but I think it meets all of your other requirements, like on device manual control, no cloud, air temp sensor and floor sensor connection etc.
There aren’t that many products out there that fit the bill, I was particularly struggling with ones that would let me set the max floor temp sensor low enough when I was comparing the spec sheets a few years back.