You can remove an individual radiator without draining the whole system. Make sure you have plenty of rag for mopping up spilled water, plus a jug and a large bowl. The water in the radiator will be very dirty, so, if possible, roll back the floor covering before you start.
Shut off both valves, turning the shank of the lockshield valve clockwise with a key or an adjustable spanner. Note the number of turns needed to close it, so that later you can reopen it by the same amount.
Unscrew the cap-nut holding either the handwheel valve or the lockshield valve to the adaptor in the end of the radiator. Hold the jug under the joint and open the bleed valve slowly to let the water drain out. Transfer the water from jug to bowl and continue doing this until no more water can be drained.
Unscrew the cap-nut that holds the other valve onto the radiator, lift the radiator free from its wall brackets and drain any remaining water into the bowl. Unscrew the brackets if you plan to decorate the wall.
To replace the radiator, screw the brackets back in place, then hang the radiator on them and tighten the cap-nuts on both valves. Close the bleed valve and reopen both radiator valves (open the lockshield valve by the same number of turns you used when closing it). Last of all, use the bleed valve to release any air trapped in the radiator.
Shut off both valves, turning the shank of the lockshield valve clockwise with a key or an adjustable spanner. Note the number of turns needed to close it, so that later you can reopen it by the same amount.
Unscrew the cap-nut holding either the handwheel valve or the lockshield valve to the adaptor in the end of the radiator. Hold the jug under the joint and open the bleed valve slowly to let the water drain out. Transfer the water from jug to bowl and continue doing this until no more water can be drained.
Unscrew the cap-nut that holds the other valve onto the radiator, lift the radiator free from its wall brackets and drain any remaining water into the bowl. Unscrew the brackets if you plan to decorate the wall.
To replace the radiator, screw the brackets back in place, then hang the radiator on them and tighten the cap-nuts on both valves. Close the bleed valve and reopen both radiator valves (open the lockshield valve by the same number of turns you used when closing it). Last of all, use the bleed valve to release any air trapped in the radiator.