Totally agree with Davy,
But feel it should also be pointed out, that fitting thermostatic radiator valves is a step forward, it still means that the boiler will keep firing (short cycling) even is all rad valves are shut and you house is toasty. The do not provide what is called 'boiler interlock'
That is a series of control elements that ensure the boiler does no fire when there is no demand for heat (rads or hot water) and can be achieved by fittng room stats, cylinder stats and motorvalves, and a multi channel programable timeclock
To show the benefit as regards the SEI grants available, €500 is for the controls, and €700 for both boiler and controls is on offer (hints to where the biggest energy savings lay)
Think of boiler short cycling as if it were a car, don't you use a lot more petrol driving stop/start across the city, than a long constant drive down the motorway, well short cycling of your boiler is the same, it is most efficient running rather than stop/start (short cycles)