Thermostat controlled radiators

Fig. 1 Thermostat for radiator (Danfoss).
Bathroom setting 4 (23 C), living-room
setting 3 (20 C), bedroom setting 2
(17 C), staircase and hallway setting
(13 C), and anti-freeze setting * (7 C).

If theromstats are used according to producer guidelines (Fig. 1), then they save energy (99 kWh/år, Average savings).

A thermostat on a radiator will maintain the room temperature it has been set to, e.g. 20 degrees in the living-room. If sunlight is streaming into the room, the thermostat will shut off, and if a chill wind blows, it will turn on.

When the room temperature drops below the optimal level, the thermostat-controlled valve will circulate hot water through the radiator. Once the radiator has heated the room, the thermostat will turn off the valve again.

In the summertime, the thermostat will turn itself off - thus there is no need to turn down the settings. The thermostat in Fig. 1 has two controls, which can be set so that they limit the amount the thermostat can be turned. This can prevent children and guests from altering the preferred heating settings.

There are good animations of how thermostat valves work available on the internet (refer to Danfoss under References; unfortunately, Danfoss does not allow direct links to the animation, so please find it yourself on their homepage under Animerede præsentationer).

General guidelines

  • Set all radiators in connecting rooms to the same approximate temperature. This provides the most efficient heating and the least exposure to drafts.
  • Exercise the valve to prevent clogging. Turn it all the way up and all the way down several times.
  • Air out the radiator. Airpockets prevent efficient circulation, and leaves the top of the radiator cool.
  • If the radiator is warmer at the top and cooler at the bottom, then it is functioning normally; the radiator is cooling the water.
  • Briefly open windows to air out the room, or set the thermostat on star (*).

Created by tanja.groth. Last Modification: Monday 31 May 2010 14:40:41 CEST by tanja.groth.