HVAC Controller

Controller for various types of HVAC systems. This block is optimized to work with at least one Intelligent Room Controller and its intelligent mode switching to control the heating/cooling system.

Rooms with presence are prioritized for the heating/cooling decision. If presence is detected in rooms that call for heat and in rooms that call for cooling, the decision is based on the higher demand.

Intelligent Room Controllers provide dedicated outputs for up to three assigned controllers.

This function block belongs to the family of thermal energy sources. It is also suitable for use with hydronic heating systems.

This block is incredibly sophisticated and far superior to energy source controllers available on the market, e.g. luxurious thermostats.

Table of Contents


Abbreviation Summary Description Unit Value Range
Mode Mode 0 = off
1 = automatic mode, switches automatically between heating and cooling, based on demand
2 = heating only
3 = cooling only
- 0...3
ϑo Outdoor temperature If this input is not connected, the value of the system variable "Outdoor temperature" is used. °
B Boost Activate second stage heating/cooling if the first stage is already active. - 0/1
Off Off Pulse: Outputs are reset / switched off.
On: Block is locked.
Dominating input.
The name of the connected sensor is used in the user interface.
- 0/1
Eh Emergency Heat Activates output (E) when heating demand = 1. Used for emergency heat, e.g. if heat pump defective. - 0/1
Fan Fan Activates output (G) and opens all Intelligent Room Controllers to 100%.
If this input is used, the fan can no longer be activated in the App.
- 0/1
H Humidity Required when output (Hmd) is connected in order to optimize indoor humidity. Note: Use the humidity reading of the most relevant room or an average value. -


Abbreviation Summary Description Value Range
W/W1 1st stage heating 1st stage heating, active if heating is required and possible 0/1
W2 2nd stage heating 2nd stage heating, active if 1st stage heating active > (Tt2s), or if parameter (∆ϑ) exceeded 0/1
Y Compressor Compressor. Varies depending on selected heating type.
For "Heat Pump with Electric Backup": active when heating and cooling.
For "Heat Pump with Fossil Fuel Backup": active for first stage heat, inactive for second stage heat.
For "Oil/Gas": active when cooling
Y2 2nd stage cooling Additional cooling, active in the same manner as second stage heating 0/1
E Emergency Heat Activated depending on input (Eh) or via app activation. 0/1
O/B Reversing valve Changes the operating direction of the heat pump. If (DirV) is deactivated: OFF for heating, ON for cooling. If (DirV) is activated: ON for heating, OFF for cooling. 0/1
G Fan Fan that moves heated or cooled air into the rooms 0/1
Hmd Humidifier Activated in heating mode if (H) < (Hs) 0/1
AC API Connector Intelligent API based connector.
API Commands


Abbreviation Summary Description Unit Value Range Default Value
minO Minimum OFF time Heating and cooling must be off for longer than (minO) before reactivating.
Note: This prevents frequent switching on and off of the heating/cooling system and thus extends the system life.
s 0...∞ 300
Sot Switch-on threshold Switch-on threshold for heating/cooling. The arithmetic mean of the demand (degree of opening * room size) of all Intelligent Room Controllers must be greater than (Sot) to activate heating/cooling. If a room with motion is calling for heating/cooling, all Intelligent Room Controllers that are in Eco mode will be opened after 15 minutes.
WARNING: Defines the minimum threshold to prevent overheating or freezing of the system
% 0...100 30
Fot Fan overrun time Fan overrun time after heating or cooling. Transports residual energy from the system to the rooms. s 0...∞ 90
Tt2s Time to second stage If heating/cooling is active for longer than the set time, the second stage heating/cooling is activated. s 0...∞ 300
∆ϑ Delta temperature second stage If the difference between the setpoint and actual temperature of an Intelligent Room Controller exceeds the set value, the second heating/cooling stage is activated. It is deactivated again when the difference reaches 0°. ° 0...∞ 2
mioϑc Minimum outdoor temperature cooling If the outdoor temperature falls below this value only heating is allowed. ° 15
maoϑh Maximum outdoor temperature heating If the outdoor temperature exceeds this value only cooling is allowed. ° 18
ϑpmic Protection temperature minimum cooling Minimum outdoor temperature for activating the heat pump in Cooling mode to protect it from damage. ° 12
ϑpmih Protection temperature minimum heating Minimum outdoor temperature for activating the heat pump in heating mode to protect it from damage.
Applies only to heating type 'Heat pump with fossil fuel backup'.
This parameter is only visible in certain configurations.
° 0
ϑpmah Protection temperature maximum heating Maximum outdoor temperature for activating the heat pump in heating mode.
Does not apply to heating type 'Oil/Gas'.
This parameter is only visible in certain configurations.
° 19
Hs Humidity setpoint If the humidity falls below the setpoint in heating mode, the humidifier is activated until the humidity exceeds the setpoint by 2. % 0...100 45
DirV Direction valve Changes the operating mode of the reversing valve. - 0/1 0


Summary Description Default Value
Heating Type Type of heating. The type determines how the outputs are controlled. -
Assign room controllers Add or remove the Climate Controller as a source for individual Intelligent Room Controllers.
Further settings (Priority, PWM, etc.) can be made in the configuration dialog of each Intelligent Room Controller.