The lockshield valve, on the side of the radiator opposite the on/off valve, may be adjusted to balance the output of your heating system. The lockshield itself is the plastic cap that covers the valve to ensure that you don't accidentally change the setting once you've adjusted it.

What side does the lockshield go on a radiator?

Systems are normally balanced by adjusting the lockshield valves usually fitted on the return side of each radiator. This ensures that each radiator circuit in the system has an equal pressure drop and receives the correct flow of hot water to heat the space in which it is fitted.

Does it matter which side of radiator flow and return?

Most modern thermostatic radiator valves are bi-directional – so can be fitted on either the flow or return pipe of your radiator. However, it's always best practice to fit the TRV on the flow pipe that enters your radiator.

What position should a lockshield valve be?

The lockshield valve should be set to a degree that will allow the radiator or radiators to maintain their desired temperature.

How do you find a lockshield valve?

A lockshield or a lockshield valve is a type of radiator valve. It connects a radiator to the return pipe to the boiler. It is one of two valves normally found on radiators, the other being the TRV (thermostatic radiator valve). A lockshield can easily be identified by its small white plastic cap.

How a locksheild valve works

Which side of radiator is Inlet?

Discovering where the valve inlets on your radiator are is fairly straight-forward and is defined primarily by the kind of radiator or heated towel rail that you have. With a heated towel rail, for example, you will normally find that the inlet position is located underneath at the bottom.

Which valve is which on a radiator?

One valve accounts for the amount of hot water that enters the radiator. The other valve, referred to as the lockshield valve, balances the system by regulating how much heat the radiator gives off. For a more detailed insight, take a look at our Radiator Valve Guide.

Does it matter which end of a radiator the TRV goes?

The vast majority of new TRV's are bidirectional and can be fitted to either the flow or return, but it is always good practice to fit them to the flow side. If a non bidirectional TRV is fitted on the return side it will create a vibrating sound as the water tries to flow though it.

Are lockshield valves one way?

Once the system has cooled down, you will have to open the lockshield valve. To do this, simply turn in an anti-clockwise direction (to the left). You can do so by hand; but if your valves are a bit stiff, use your lockshield valve key, a spanner, or the wheelhead valve cap instead.

Which way does a radiator lockshield valve open?

Most lockshield valves have a plastic or metal cover. You should remove these and open all of the lockshield valves completely. This requires that you turn them anticlockwise. You should also fully open the TRVs (thermostatic radiator valves).

How do I know which is the flow side of a radiator?

The flow of a radiator is typically on the left as you look at it stood up or attached to the wall.

How do I know which is flow and return?

Hi, turn the heating on and the pipe that gets hot first is the flow. Switch on your heating from cold. The pipes on the heating circuit that heats up first will the flow pipe, the other wil be the return. The Flow pipe gets warm before the return pipe.

How do I know which way my radiator flows?

Check the valve itself and there should be a little arrow near the outlet. If the arrow points away from the valve it needs to go on the return side of the radiator, if it points into the valve it should be on the flow side.

Do all radiators have a lockshield valve?

Lockshield Valves Explained

A lockshield valve is slightly different from manual and thermostatic valves as it controls how much water can exit a radiator. Every radiator has one, and you need them to make sure all the radiators remain balanced in your central heating system.

What is the difference between a lockshield and radiator valve?

The Lockshield valve restricts hot water flow to radiators to help balance the entire system as a whole. Other radiator valves can be used to help adjust the temperature of a radiator to help heat or cool a room.

Do radiators have a flow direction?

The new radiator is marked for the direction of flow; through the valve and in at the top of the radiator.

Should both sides of a radiator be open?

You should open both of the valves on all of your system's radiator when you are starting the radiator balancing process. You will most likely need to use pliers to open the lockshield valve.

Do radiators have a flow and return?

The flow pipes are connected to one end of the manifold in a number of radiators, and then return to the other end. But both the feed and return microbore pipes are connected to the same end of the radiator.

Does inlet and outlet matter on a radiator?

Yes it does. They have a baffle or diverter near the flow. So it is imperative that the flow is connected to the inlet port ,and return to the outlet port.

What do the arrows mean on a TRV?

Look on the metal body for some arrows. If there are two, at 90°, then the TRV can go on either end and any way round, i.e vertical or horizontal. If there is only one arrow, it can still go on either end but the arrow must point in the direction of flow (towards rad on flow, away from rad on return).

Are both radiator valves the same?

Generally, there are two different style radiator valves (that are adjustable by the user) available. These are manual valves and Thermostatic Radiator Valves (also known as TRVs). Manual valves are quite simple devices that you can think of like a tap in your home.

What does the snowflake on a radiator mean?

Frost protection mode. Snow flake symbol- Frost protection mode, In cold weather protects the radiator from frost. Allows Minimal flow. 2-3-4-5, the first line being coolest to the last being the hottest.

Why does a radiator have two valves?

Each radiator will have two valves. One will control the amount of hot water that enters the radiator and the other will balance the system by controlling how much heat comes out of your radiator.