You can accomplish something similar with a smart thermostat such as the Nest or Ecobee, coupled with a room sensor.
I agree, I have an Ecobee with room sensors in a couple key places. I can select which sensors for temperature to use during which scheduled times or let it auto detect occupancy.
And I can control the thermostat from a phone our web browser anywhere I have a connect.
I was hoping TS would tell us why he wanted to make it mobile in case he had some odd edge case that a smart thermostat wouldn't work with.
I guess a better explanation would have helped. So this is for a 2 zone hydroponic floor heating (with a thermostat for each zone since they are controlled independently).
Ok I am with you so far, 2 independent zones each controlled by its own thermostat.
The reason I want to make the one thermostat mobile is because at the moment its located near the heat exchanger and manifold which generates a lot of heat so the reading isn't correct for the room temperature.
Ok, I am still with you. One your two current thermostats was poorly placed in a hot spot.
If I relocate it to the other side of the room I would have to run the wire either on the surface of the walls and ceiling or bust up the drywall and then patch.
How is your house built; basement, slab on grade, other? I have a basement and an attic and I've run low voltage wiring from the basement into first floor walls, un the chase for the return duct the the second floor, and from the basement to the attic and down a second floor wall; all without busting up drywall. A house without an attic or a basement would be difficult, but if it had either, it might be possible.
To make things easier I was thinking of adding adding a rf transmitter to the thermostat and a rf receiver to the control panel that manages the zones.
Ok that seems like a reasonable path to start thinking about.
Anyhow the smart thermostats won't work in this scenario as they don't run zones independently.
Now I have gotten lost. I think I understand that you currently have 2 thermostats connected to a control box at the heating system; when one thermostat calls for heat the control box turns on the heat to the zone associated with that thermostat.
Are you saying that installing any smart thermostat into the current system, will result in the smart thermostat overriding the other thermostat? If so is this a specific issue related to the control board you have? At least some smart thermostats, like ecobee (which I have in my one zone system) are "compatible with most zone board models, however, to ensure all features are supported with your zone board or zone controller, please contact ecobee Support."
When one sensor calls for heat all zones get heated.
I think I have confused myself thinking about your system. To this point I have been thinking in terms of thermostats (and a smart thermostat would trigger all zones to heat).
It would require a smart thermostat contacted to the control panel and an additional sensors tell the thermostat to turn on or off is expensive.
I do not know what budget you are looking to come in under Ecobee with one remote sensor runs about $228 on Amazon; which is not cheap, but as I said, in my climate the cost of a system failure can big. I know several people who have had failures either on vacation or on a really cold day that resulted in damage (including burst pipes) resulting in up to 11k of damages plus the hassle of dealing with it.
Anyhow after more research there are lots of thermostats including smart ones available from china made specially for Europe that do this sort of this but finding one that runs on 110v is the challenge.
Do you have a link to the kind of product that you believe that will fit your needs?
I feel like there must be a simpler way to accomplish what you want, though I do not doubt it can be accomplished via your line of thinking.