Which End of the Radiator To Fit the TRV

This is a common dilemma that people have and an oft asked question at DIY Doctor. At one end of the radiator the TRV will be fitted and at the other there will be a lockshield valve, however many are concerned if the smart TRV should go at the flow or the return side of the radiator.

This is a justified concern given that in the past both the TRV and the lockshield valve that were available were only able to work with the flow in one direction. However this in not the case now and most, if not all, TRVs are universal, meaning that the flow can be either way through them without making and alterations to them. This means that there is no restriction to which side of the radiator they can go.

The things that you should consider when choosing which end of the radiator the TRV should go are:

1.Easy of Access: There is no point have a TRV which you cannot get to and change the setting when needed. Don’t locate them where they are likely to be blocked by furniture or are hard to reach

2.Air Flow: The TRV functions by controlling the flow to the radiator based on the temperature of the room (not the radiator, which is a common misconception). In order for it you work efficiently it is necessary to have a good air flow around the TRV so that it is working on the actual room

temperature. This will help the radiator as they work predominantly by convection – air circulating around the room – and not radiation (another common misconception), as a good airflow to the radiator, and TRV also, will make the radiator more effective. Don’t site the TRV behind curtains, furniture or doors which will be open most of the time

3.Aesthetics: Site them where they will look most attractive. If there are a number of radiators in a room, site them on the same side to create the effect of uniformity. Ultimately this is down to your personal choice

Always check the manufacturer’s instructions for any specific instructions and tips.