3 radiators not getting hot

[wazo]

Hello All,
I am in need of some assistance!
I have recently hired a corgi registered guy to install my new Sabre boiler, he has fitted the boiler to my existing piping system.
Now the first 2 radiators are getting hot but the other 3 are stone cold,
I am in a 2 bedroom ground floor flat. He doesn't seem to know what the problem is because my old system worked fine (I had a separate cold and hot water tank and potterton boiler)
He thinks that the new radiator thermostatic valves may be causing the problem? I have a small leak in one of the radiators-I am getting this replaced today.

Any ideas?
Thank you in advance

 

[seco services]

is the flow pipe hot to the rads ?
are these rads on the same part of the system ?
remove the trv head and see.

 

[namsag]

I take it he has done the basics of shutting off all the rads except one and sticking the boiler up to just under 3 bar to force any air that may be trapped out the way