Radiator replacement:
 A single radiator replacement can take between 2-2.5 hrs. Depending on location – 1st floor or ground floor, number of radiators, size and type of system. Is the new radiator being fitted on the existing pipework? If the radiator is different in size the floor boards might need to be lifted in order to alter the pipework to suit. Alternatively you can have the pipework surface mounted if you do not wish your floor to be tampered with. After effective replacement of the radiator the system needs to be refilled, vented and topped up with inhibitor. 

Taking the above information in consideration you can expect like for like replacement of 3x radiators to take a full days work( taking into account draining down, refilling and balancing the system).

 Radiator valves replacement:

 Replacement of set of radiator valves can take an hour or slightly over, including draining down and refilling of the system. For instance replacing the valves on 6-8 radiators would required a full day’s work. Radiator valves can cost anything between 10£-50£ depending on the brand.

Relocating a radiator:
Changing the location of a radiator would require the system to be drained down and refilled on completion. Also the floor boards would have to be removed in order to reconfigure the pipework. Alternatively the pipework can be surface mounted