hi dave i have checked wickes website and the trvs i have used are :-
Fully reversible for installation on the flow or return pipes
basically the rads are not getting hot in 2 rooms, the small double rad in my bathroom is luke warm and there is no air in it, and the one in the kitchen is...
i recently added 3 rads to my existing worcester boiler system and think i have muddled up the ends that should have the rad valves on, one radiator at the far end of the circuit was cold so i balanced the upstairs rads by opening the feed end one turn out from closed position and that fixed it...