The radiator thermostat: The underrated measure when it comes to energy-saving:

What do the lines actually mean on a radiator thermostat valve? What is the correct setting? How can you save heating costs?

Each heating valve that is to be adjusted manually has a unit scale which usually ranges from 1 to 5. Setting one represents the room temperature between 12-16° Celsius. Raising this by one setting causes an increase of the room temperature by approximately 3° Celsius, so that at Setting three the room temperature will reach approx. 20-21° Celsius.

https://www.arqum.de/wp-content/uploads/2016/08/Fotolia_96233137_L.jpg

Inside the valve is a cartridge which contains a gas or liquid and serves as a temperature sensor. In the event of a cold ambient temperature the gas or liquid is compressed, while it expands when the temperature is raised. The thermostat controls the hot water supply through expansion and compression. Turning the valve to the highest setting is therefore by no means a quicker way to heat the room; it only increases the desired room temperature to approx. 27° Celsius!

So, how can we save heating costs? On the basis of the above-stated effect of the thermostat ambient temperature, it is important that nothing is placed near the thermostat and that the air can circulate freely. Through consistent adjustment of the thermostat valves to the respective room usage (e.g. bathrooms warm, bedrooms cool) and an adequate adjustment to the time of day and user pattern, you can save up to 10% of heating costs. The simplest way to do this is to use programmable thermostats, configuring an individual heating profile for each room. The advantage is that rooms (e.g. bathroom) can be heated in advance to when it is to be used. Most radiators can be retrofitted with programmable thermostats without professional help. Many of the new devices can also be centrally programmed and controlled using WLAN or BlueTooth via a PC or an App.

Quellen: www.co2online.de, www.heiz-tipp.de