A wall mounted thermostat module configured to control indoor environmental conditions through a heating, ventilation, and air conditioning system, HVAC, the thermostat module comprising: a display configured to provide a home screen configuration (80,81, 82) of a mode of the wall mounted thermostat module, wherein: the display includes one or more different areas configured to display information at predefined locations using one or more fixed segments and/or symbols, wherein each fixed segment and/or symbol has a separate and distinct fixed position on the display independent of the home screen configuration displayed on the display; and the display is associated with one or more soft keys, each soft key having a separate and distinct fixed location on the display wherein the soft keys include one or more labels, wherein each of the one or more labels is one of the fixed segments and has a separate and distinct fixed location in the soft key on the display; a processor connected to the display; one or more sensors, configured to provide one or more HVAC system related parameters about an indoor space, connected to the processor; and wherein one or more HVAC system related parameters can be changed at the thermostat module, where a quantity of HVAC system related parameters that can be changed at the thermostat module is customizable and parameter types of HVAC system related parameters that can be changed at the thermostat module are customizable; characterised in that a plurality of preconfigured home screen configurations are loaded on the wall mounted thermostat module; and wherein the home screen configuration of the mode of the wall mounted thermostat module is selected on the wall mounted thermostat module from the plurality of preconfigured home screen configurations loaded to and located on the wall mounted thermostat module for the mode and wherein the home screen configuration selected from the plurality of preconfigured home screen configurations has a configuration layout that is modified at the wall mounted thermostat module and configured to display information at predetermined locations using the fixed segments and/or symbols of the display by selectively enabling and/or disabling desired fixed segments and/or symbols and to selectively display a label of the one or more labels at its distinct and fixed location on the display in each of one or more of the one or more soft keys. a display configured to provide a home screen configuration (80,81, 82) of a mode of the wall mounted thermostat module, wherein: the display includes one or more different areas configured to display information at predefined locations using one or more fixed segments and/or symbols, wherein each fixed segment and/or symbol has a separate and distinct fixed position on the display independent of the home screen configuration displayed on the display; and the display is associated with one or more soft keys, each soft key having a separate and distinct fixed location on the display wherein the soft keys include one or more labels, wherein each of the one or more labels is one of the fixed segments and has a separate and distinct fixed location in the soft key on the display; the display includes one or more different areas configured to display information at predefined locations using one or more fixed segments and/or symbols, wherein each fixed segment and/or symbol has a separate and distinct fixed position on the display independent of the home screen configuration displayed on the display; and the display is associated with one or more soft keys, each soft key having a separate and distinct fixed location on the display wherein the soft keys include one or more labels, wherein each of the one or more labels is one of the fixed segments and has a separate and distinct fixed location in the soft key on the display; a processor connected to the display; one or more sensors, configured to provide one or more HVAC system related parameters about an indoor space, connected to the processor; and wherein one or more HVAC system related parameters can be changed at the thermostat module, where a quantity of HVAC system related parameters that can be changed at the thermostat module is customizable and parameter types of HVAC system related parameters that can be changed at the thermostat module are customizable; characterised in that a plurality of preconfigured home screen configurations are loaded on the wall mounted thermostat module; and wherein the home screen configuration of the mode of the wall mounted thermostat module is selected on the wall mounted thermostat module from the plurality of preconfigured home screen configurations loaded to and located on the wall mounted thermostat module for the mode and wherein the home screen configuration selected from the plurality of preconfigured home screen configurations has a configuration layout that is modified at the wall mounted thermostat module and configured to display information at predetermined locations using the fixed segments and/or symbols of the display by selectively enabling and/or disabling desired fixed segments and/or symbols and to selectively display a label of the one or more labels at its distinct and fixed location on the display in each of one or more of the one or more soft keys.