Can I read temperature and motorposition from tado thermostats

hoegge

Hi'

I've used Danfoss link for a while, but it is closed system and they really screwed their customers, so I'm looking for something else. Since I need to have the radiator system and my air to water heat pump play together, I would like to (I need) be able to read:

1) Temperatures in rooms (not sure if tado thermostats have a temp sensor or only works with rooms sensor - in that case read those)

2) Read the thermostat position - what is the current setting (between fully closed and fully open)

Is that possible with tado - and if not - any other systems?

wateroakley

@hoegge 1) The room temperature can be read by the SRV (on the rad valve), wireless room sensor, or wired thermostat.

2) The SRV position is 'open' or 'closed'. (Unlike a TRV, where the wax or liquid in the head will expand at higher temperatures and push down the pin to close the valve.)

hoegge

Hi Wateroakley -

Thanks - but I wondered how I can programatically read it from the SRV or SRT.

If the valve can only be open or closed, I think it is probably not a system for me. That will require it to open and close often to modulate the heat, which will require either too much power (battery) or result in to fluctuating temperatures, I guess, and not be very good for a heat pump, with resistance in the system randomly changing abruptly.

GrilledCheese2

@hoegge Tado does have an unofficial API to read values for each device. You can read the room temperature and the setpoint. You can also read the heat demand as a percentage value. Not sure how the heat demand relates to the SRV motor position. According to some users on here the SRV is not simply on/off - there appears to have been a firmware upgrade at the end of last year to add this functionality.

hoegge

Thanks @GrilledCheese2 - I also heard that at some point, but was not sure.

But would be nice, if it was possible to read that from their documentation. Also I'd rather like to be independent of any vendor's API and cloud solution, since you tend to get stuck and abandonned suddenly.

GrilledCheese2

I agree, with an API that's not officially supported there's a real chance of getting stuck. Just for info - the Home Assistant community has documented a lot of the interface and some of their projects are available via GitHub.

hoegge

thanks @GrilledCheese2

davidlyall

@wateroakley

I don't think that's correct about the TRV position being only fully open or closed. I hear my TRVs perform either short or long adjustments with long ones corresponding to going from no lines to 3 lines (or the other way) and short adjustments meaning a change of one heating line in the app.

I believe there are 4 positions - closed, 33%, 66% and 100%