In order to ensure an even distribution of hot water to the radiators in a system, youll need to “balance the system”. Often, the radiators near the boiler/pump would often be warmer than the radiators further away, balancing the system will even out the flow of the hot water.
To do this we use the lockshield valve which is normally hidden under a push on cover at one end of the radiator. Adjusting these valves will control the flow of water to the radiator. By partially closing the valves, flow to the radiators nearest the boiler can be more limited than to those further away. To lower the water temperature at the outlet pipe, the lock shield is closed to increase the temperature when the valve is opened up.
The idea is to get the temperature drop across each radiator to be about 12 C 20 F. The simplest way to measure the temperature drop across the radiators is to use a set of radiator thermometers. These clamp-on thermometers have springs which hook around the inlet and outlet pipes of a radiator. They can be found at any DIY store.
Before you start, ensure the system is turned off and let the water cool off.
Open the lock shield valve and the control valve utilizing an adjustable spanner. This is the valve you use to turn the radiator on and off.
Fit the radiator thermometers to the inlet and outlet pipes of the radiator which is nearest to the boiler, and turn the heating back on.
Close the lockshield valve on the first radiator to almost closed, as the temperature of the systems comes up, slowly open up the valve until the temperature difference between the two radiator thermometers is about 12 degrees C 20 F.
Move the thermometers to the next radiator far from the boiler. Close the lockshield valve and adjust it until the temperature difference increases to about 12 degrees C the temperature difference will probably begin at less than 12 degrees as both valves are fully open.
If you repeat this for all of them in order, you ought to have a balanced system so that all radiators heat up efficiently.
When the radiators in a system have been balanced, the valves should not need to be adjusted again, unless the radiators or the pipes are changed Here .