Your new radiator will probably have four holes or tappings – one at each corner -and each one will have a female screwed thread. How you connect the radiator up to your system depends on the way in which the old one was fitted. Nowadays it is usual for the flow and return connections to be made to the bottom two holes but. of course. if your system had the flow pipe at a higher level then you’ll have to reconnect it in the same way.
Fit an air-valve into one of the top tappings. First wrap PTFE thread sealing tape anticlockwise round the male thread of the valve and then use a radiator key that grips inside the body of the valve to screw it home. Unless your radiator has a top inlet the other top tapping must be plugged with a blanking off plate. This should also be wrapped with PTFE tape and screwed home in the same way as the air vent.
You’ll then have to fit tail pieces and coupling screws (either new ones, or the ones from the original radiator if you can remove then)) on to the new one. Again wrap each thread with PTFE tape before fitting them. Its a good idea to buy new wail brackets for your replacement radiator. After all. you can’t be sure the old ones will be suitable. You should drill and plug the wall and then fix the brackets in place. Fit the radiator so that the inlet end is a few millimetres higher than the outlet valve. This W make venting easier. You can now fix radiator in place and connect the coup nuts to the hand-valve and Jock-shield va and screw them up tightly.
You’ll have to open the air-valve at the tcc of the radiator so that the air in it car ze displaced as it fills with water. All you oz slowly open the hand-valve and allow 7-S. radiator to fill. When water starts to flow f rd– the air-valve you’ll know all the air has bee- displaced and you should immediately close the valve. Finally, open the lock-shield value by the same number of turns and part turns took originally to close it.