5
1 Introduction
1.2
Application
The flue gas thermostat is used for monitoring flue gas temperatures on solid-
fuel boilers in dual operation with oil-heated boilers.
Operation
The flue gas thermostat operates on the principle of rod expansion. The
immersion tube and the metal rod inside it have different expansion coeffi-
cients, producing a temperature-dependent difference in length which acts on
the microswitch through a mechanism. The microswitch is operated above a
set temperature limit. After the immersion tube has cooled down by approx. 10
to 30 °C, the microswitch is reset. Should the immersion tube break, the circuit
is opened permanently.
A
Caution
When burning solid fuels, it is necessary to ensure that they are approved in
accordance with the corresponding local regulations on emission protection. If
this is ignored, corrosive gases may destroy the thermostat!
