Thermostatic radiator valve - heating control in radiators

Thermostatic radiator valve (TRV) is a small device that regulates heating in radiators. It is one of the most basic heater accessories. It enables control over the temperature in every room, adjusting it according to the needs. This seemingly simple valve is very important for the whole heating system. Radiators will not work properly if their thermostatic controllers are faulty or unfitting. Such situation may cause higher heating bills. How to choose the right valve for your heater so that it will provide you real comfort? Use the information below to make the best decision and choose the perfect TRV for your radiator.

Table of contents

  1. Structure and operation - all one should know
  2. How to choose the right thermostatic radiator valve?
  3. Typical thermostatic radiator valves
  4. Length of the spindle
  5. Thermostatic controller types
  6. How to install thermostatic controller on a heater?



Structure and operation - all one should know

Radiator thermostats are made of 5 main elements:

  • thermostatic head,
  • sensor (filled with liquid),
  • rising spindle,
  • securing ring,
  • metal coil.
The device works using the sensor filled with liquid, located inside of the valve. The liquid expands or shrinks depending on the temperature of the surroundings. When it’s hot in the room, the volume of the liquid increases. The sensor expands and presses on the pin. The pressure moves the spring, closing the valve. As a result the flow of the liquid inside the installation decreases, causing the heater to cool off. On the other hand, when the temperature of the room drops, the volume of the liquid gets reduced. The pressure applied to the coil decreases and the valve unlocks the flow of the heating medium. In consequence the heater warms up.

How to choose the right thermostatic radiator valve?

When choosing thermostatic controller for your room heater, pay close attention to several issues. The most important matter is the particular model and the right size of the thread, fit for the radiator tail. To work properly, TVRs must be perfectly connected with heaters. Otherwise the thermostat might malfunction and the whole system will be insufficient.

Typical thermostatic radiator valves

There are several sizes of radiator valves. It is important to choose a valve, which has the thread of the same width as the heater tail. The most common thread sizes used for radiator valves are:

  • M30x1.5 - standard,
  • M28x1.5,
  • M32,
  • M23x1.5.

Length of the spindle

Another highly important issue is the length of the spindle. Too long or too short spindle might disturb the proper functioning of the heater. It would cause the heater to work inefficiently.



Thermostatic controller types

There are two types of thermostatic radiator valves. They are different according to the position of their installation:

  • Vertically - reinforced, with raised sensor. Such valve can be covered or exposed to draughts. Its head is designed specifically to prevent theft and third party access. Therefore this type is suitable for public spaces.
  • Horizontally - because of their sensitive sensors, such valves should not be covered or exposed to cold airflow.

How to install thermostatic controller on a heater?

Important When selecting a thermostatic radiator valve, pay attention to its size and type of the connections. Properly chosen TRVs are easy to fix onto heaters. If the connections of the thermostatic controller do not match the heater’s tail, you can use a special adapter. It allows to install the device even if the threads do not fit.

Thermostatic radiator valves are available to buy as singular products, however many vendors sell them along with radiators. They can be also bought with other accessories for heaters that enhance their functionality. Choosing a valve one should consider the heater on which it is going to be installed, as well as its location.

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