TRV or not TRV? That is the question

[Londi]

right lads the missus is getting on my case about sorting the heating out as we are due our first child soon,she would like the heating on low all the time and for the upstairs rooms to be at a constant temperature rather than it going from cold to hot then cold again when the heating goes on/off.

is replacing the ordinary valves with TRV's the answer or is there another way and which way is best?

current valves need replacing anyway and are just the basic type like this but about 30 years old.

or these

and what does 10 or 15 mm sizes refer to?

cheers in advance

 

[breezer]

trv's control the heat in any room providing the main stat has not turned off the boiler

10 or 15 refers to the inlet diameter of the pipe (most common is 15mm)

and you must leave at least one rad with no trv, most common one is the bathroom