Which Types of Valve Do You Find On a Radiator?

often feel confused. Do you bleed a TRV? Do you have to leave the bleed valve open? It can all be a bit confusing if you aren’t used to the terms. Here, we have produced a glossary of terms for you to refer to whenever you’re stuck wondering what a particular valve might be. 

·         Manual valve: these are usually found to the right hand side of the radiator, at the bottom. They control the amount of fluid (usually water) within the radiator. This, in turn, controls the temperature of the radiator. 

You set the manual valve to open fully and the radiator reaches full temperature, and you set it to open half way, and it reaches half the temperature. 

You would use these different settings depending on the room. For example, in your living room, you probably want the valve to open fully. While in the bedroom, you probably want it to open ½ way – most people prefer colder bedrooms.

    Thermostatic radiator valves (TRVs): these are relatively new types of valve, and as such, tend to create a lot of confusion. 

These are the valves that you find to the right of the radiator, and which are fairly large.

 These replace manual valves. You will find TRVs on all manner of radiator, from modern aluminium radiators to the older cast iron radiators. 

TRVs control the heat output. Manual valves did this too, but the difference is that TRVs do it automatically. You set them to a particular setting, and then they open and close themselves as they cool and heat, so that they can remain at a constant temperature. They’re very clever, but they do all of this via wax. 

·        Bleed valves: you will always find these at the top of the radiator, and usually towards the right hand side. These are special valves for releasing air from the system. They require a special key called a “radiator key” or “bleed key”. These are largely universal, so if you lose your key, you can pick up a replacement from your local DIY shop. 

If you would like further help and advice about the various types of valve found on a radiator, then please visit Designer Radiator Direct