Lock shield valve adjustment

It was common practice in older systems to have a heat loss radiator. (Normally bathrooms as it is the room needing to be hottest what with moisture) but nowadays we have to install automatic bypasses so it's no a requirement. If your system is old than it needs one radiator that wont shut off, that doesn't mean it has to be fully open at all on the lock shield end. Just means open and wont shut off. Adjust all rads to balance the heating system to equally spread the heat around all radiators. But keep in mind not to close off the bathroom rad to much that it's off

On older systems one radiator, typically a hallway or bathroom was used as a bypass to prevent the boiler overheating, the locksheild valve is used to balance the heating system, it’s ok to use the valves for this purpose if it helps the system with even heat output on the other radiators, would advise one radiator left as a bypass without a thermostatic valve.

Lockshield Valves, are the valves without the head with numbers on ( TRV valves ) and they are used to control the amount of water that flows out of the radiator into the return pipework. This allows you to "balance” the radiator, ensuring the water is distributed evenly across your property and helping your radiators to heat up at the same rate. The best way to balance the systems is to gradually start closing the lockshiels valves from the farthest radiator towards the central heating pump or the boiler. That way you cause a restriction in the flow of water going back to the Boiler and it will allow more water flow to the farthest radiator. If you have a combi Boiler is better to leave the radiator with lockshield valve always open, but not necessarily fully open as this can disbalance the system.