Boiler information

The boiler thermostat

Is a part of the boiler and measures the water temperature in the boiler. If it is set at e.g. 70°C it will take care that the boiler temperature will remain constant about 70°C. Therefore, it is also called « constant water temperature control ». For some boilers this is necessary since corrosion problems may occur if the water temperature falls beneath a certain limit.

On the other hand the consequence of this control type is that, the boiler constantly is at a high temperature and will have high stand-by losses. This causes a significant drop of the effciency on annual basis, especially when the boiler is not well insulated and when the boiler is oversized.

Even with a boiler thermostat it is possible to control the water temperature in the distribution circuit. This can for instance be done by installing an automatic 3-way valve after the boiler. This principle however is mainly used in larger installations.

The principle a boiler thermostat and automatic 3-way valve is shown in figure 1.

Figure 1