Room thermostat with TRVs ?

[Fixitrite]

What is the reason behind the current trend of fitting room thermostats in place of or , in conjunction with TRVs ?

Years ago the trend moved away from room therms to TRVs , the current trend is for room therms .

Why the reversal ?

 

[DP]

Fitting TRVs, I say tongue in cheek, is a plumbing solution. Boiler will modulate as demand decreases but runs for the duration of the demand.

Many house I go to have TRVs set to max (might as well not have them). Fitting TRVs and a roomstat is the way forward to fuel economy. TRVs sense temperature rise due to 'external' heat sources e.g. sunlight, kitchens, living room fire etc and roomstat switches the boiler off when ambient temperature is achieved (no TRV where the roomstat is fitted). TRVs do not switch the boiler off.