Set the gas heater thermostat

The control mechanisms in modern gas heating

Modern gas heating is usually controlled by two or three thermostats. This also applies to modern heating systems that run on oil or pellets. Solid fuel heating, district heating or alternative systems have different control mechanisms.

• There is a control unit on the gas heater. In this thermostats ensure the correct flow temperature. You must also make settings here for systems that are controlled via an external thermostat.
• There are also thermostats on the individual radiators. You can use this to set the temperatures at which the radiator of warm water is traversed. You use it to regulate the heat output of the individual radiators.
• A room thermostat is also installed in some heating circuits. You can use this to regulate the temperature in individual rooms. This thermostat is often used completely incorrectly and can cause malfunctions.

Setting the flow temperature

Modern gas heating is controlled using so-called heating curves. These curves assign a flow temperature to a specific outside temperature. By choosing the curve you influence the thermostat, which is responsible for switching the burner on and off. The curves are determined by two parameters, these are the level and the slope. In order to assess the setting, any room thermostat must be set to approximately the desired room temperature. Set the radiator thermostats to a medium setting.

• Move the curve up or down over the level. If it is always too warm in the rooms in winter, regardless of the outside temperature, slide the curve downwards, if it is always too cold, move it upwards.
• The slope determines how much the thermostat changes the flow temperature when it gets colder or warmer outside. If you have underfloor heating, choose a flat curve. A steeper curve is necessary for radiators. The worse the house is insulated, the steeper the curve has to be. If the house is too cold when the outside temperature is very low, you will need to choose a steeper curve.

Set the radiator thermostats

If the heating curve is set correctly, it should be pleasantly warm in the rooms with a medium setting. Only change the settings of the radiator thermostats if there is no room thermostat in the room.

• Do not turn the thermostat all the way up or down when you want to change the temperature. Just turn it up or down a little. the heater heats at full power or not at all until the newly set value is reached. The lowering or heating does not run faster if you turn off the thermostat completely or turn it up. Mark this setting so that you can return the controller to this position at any time.
• If you want a lower temperature at night or in your absence, turn the thermostat down one level. It does not make sense to use the lowest setting for a long time. The rooms should not get too cold.
• Set the thermostats to the lowest setting or completely off while ventilating. Then set it back to the marked value.

Central regulation of the room temperature

The room thermostat is mostly a relic from the times when heating was not yet controlled by an outside sensor. If you do not want to remove it, you should note the following.

• If you lower the temperature using the radiators, the thermostat will send a signal to the heater that heat is needed. The heating starts. However, since the return temperature is almost identical to the flow temperature, the heating switches off again immediately. The signal from the room thermostat will switch it on again immediately. If there are no other consumers in the heating system, this process will continue all the time. Therefore, you may only lower the temperature using the room thermostat.
• Since the thermostat switches off the heating when room temperature is reached, it can get bitterly cold in other rooms. The heating goes out when it is warm enough in the room where the thermostat is hanging. Especially if this is set very low, there is no chance of bringing other rooms to reasonable temperatures. You should therefore not set the temperature on this thermostat too low.

The tips on radiator and room thermostats apply to all types of heating, the setting of the heating curve only applies to modern gas heating systems and some oil or pellet heating systems. Coke, wood or coal heating react differently.