3 Top Tips for Radiators and Valves.1). All radiators come with two valves. One is called a lock-shield and the other either a ‘wheel head’ or a thermostatic radiator valves (TRV). The ‘wheel head’ and TRV are used to turn the radiator on and off. The lock-shield, on the other hand, is set for each radiator when the central heating system is first installed. They control the resistance to water within the radiator and as such ensure that all radiators in the house get hot, as opposed to one or two getting desperately hot whilst the rest remain stubbornly lukewarm or just plain cold. With this in mind, the lock-shields are usually covered by a lid that stops you accidentally turning them and altering their setting. If you do need to close a lock-shield completely, for instance when changing a radiator, it’s important that you count the number of turns you make so that you can set it back to its original setting afterwards. A Walworth Plumber fits radiators.Two Tips When Fitting a new Radiator:1). If you’re using the old valves from a radiator when you fit a new one you may as well use the old tails. To remove the tails fit a radiator spanner inside the tail and turn. In the old days these always used to work but these days the internal size can vary so much you might want to opt for the adjustable version. Also, many tails can now be unscrewed with an adjustable spanner on the outside. Walworth Plumbers replace valves.2). Most of the time the radiator valves have a bit of movement in them allowing you to push the pipework down or lift it up a little. Check to see if this is the case, and if it is, take your measurements about midway so you have room for adjustment in case you get any measurements wrong. If one valve and its pipework has far less movement than the other use this site for your measurements. Always remember that you want the base of the radiator about 150 mm above the floor.