Bedroom radiator will be sized to heat the room to 16 degrees,
That does not really work, as you don't run them at the same time, and the key phrase is recovery time, i.e. from a holding temperature lets call it eco how long to reach comfort? Specially for those not retired, it needs to detect your phone is travelling towards home, and heat up first room which is going to be used, before you get home, so basic eco to comfort in an hour or less.
We burn less gas we used to - partly because we got the heating zoned. I don't want a heated bedroom in the middle of the day, and I don't want a heated sitting room when I'm about to go to bed.
Yes we do the same, each programmable TRV forms a zone, but to work well you need the rooms being used to be able to transmit the minimum output of the boiler into the room, or boiler will cycle off/on all the time, so radiators need to be larger.
thanks for pointing out that trvs don’t modulate
Early TRV's were designed to be open or closed, but modern ones do modulate, and will maintain a radiator warm all day rather than turning off and on. But clearly that only works where the boiler also modulates, my TRV's I hear the motors running as they try to heat up the room when boiler not running.
our gas boiler does not modulate
So same as my oil boiler, the problem is the TRV may open, but can't heat room until boiler kicks in, so I would set the wall thermostat to raise 0.5ºC every two hours to ensure the boiler regularly runs, my problem is the hall cools too slowly, I can adjust heat up speed with lock shield valve, but no way to adjust cool down speed.
I have altered the house by fitting better double glazing, so waiting to see how it goes, but seems likely I will fit a second wall thermostat to ensure boiler fires up, likely one which can be paired to a TRV, at night wife's bedroom is worst room, so change that TRV heat for a linked one, and living room some times too slow to heat up, so third thermostat in that room. At moment two thermostats, two pumps, and two motorised valves so main house and flat under main house are independent.
But books say wall thermostat should go in a heated room, with no alternative heating and no doors to outside on lower floor, that leaved the shower/toilet as all other rooms have door/s to outside, and two alternative heating, so the book idea does not work, 6 sets of doors into the house, 3 x patio doors (double) and 3 x single doors, even two doors in the doors (cat flaps) so only option is common sense.
