I did that too, TRVs everwhere exept a towel rail in the en-suite. I doubt it was a requirement at the time (25 yrs ago?), although it was all* DIY so i didn't pay much attention to regs.
*DIY except for commissioning the boiler and putting in a new larger gas connection from the meter. I left those jobs to the pros.
The one without the TRV is supposed to be the one where the roomstat is, so that you don't have two stats competing to control the same space. My roomstat is in the hall, so I just leave the hall TRV wide open instead of removing it, then I can easily move the roomstat elsewhere if I want to.
Thanks for the data, I have just last week installed Home Assistant on an old 2012 MacBook Air. I'm in the process of exploring the various options for monitoring various devices,
If you're interested in the difference between timed and continuous running, you can download the Heating Degree Day data for your nearest weather station from
here. Heating load is proportional to the difference between the inside ant outside temperature multiplied by the time over which the difference exists: degree days, so once you have your HDD data you can divide your energy consumption in kWh for any given period by the HDD for the same period. Since you have time in both the numerator and denominator, if you put them in the same units they cancel out, and you're just left with power divided by temperature (W/K instead of kWh per HDD).
I think you'll need a substantial amount of data though, to average out random fluctuations
