How to replace a radiator valve

Drain the heating system. As it drains, open the vents on the upstairs, then downstairs radiators.

Read more: How to drain a central heating system

1. Undo the nut that connects the valve to the radiator by turning it counter-clockwise. To stop the valve rotating, hold the body of the valve upright with a second spanner.

2. Undo the cap nut that connects the pipework to the valve body by turning it clockwise. Lift the valve away. Let the cap nut slip down the pipe.

3. If the new valve isn't compatible with the old adaptor, undo it with a hexagonal radiator spanner. Clean the threads inside the end of the radiator with wire wool.

4. Screw the new adaptor into the radiator. Run a few turns of PTFE tape around the threaded end of the adaptor first to make a watertight seal. Check that the cap nut on the pipe can be threaded onto it.

5. Thread the cap nut on the adaptor onto the end of the new valve. Do it up finger-tight. Then tighten with a spanner. Brace the valve body with the second spanner as you do this.

6. Slide the cap nut up and connect it to the valve. Then refill the system and bleed each radiator to get rid of trapped air.

7. Close the radiator vents one by one as the water level rises. Check for leaks and tighten cap nuts a little more if necessary.

 

 

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