Documentation HVAC

At the Unit itself

Wiring to the Panel from Furnace


The HVAC controller is a relatively simple block that offers many options to allow control over the more complex end of the HVAC system spectrum. This block goes hand in hand with the Intelligent Temperature Controller and can be seen as the “relays of the Thermostat”.

The Basic Setup to realize HVAC control consists of 2 Intelligent Temperature Controller with ione HVAC Controller per Furnace. The control of the Furnace itself is done through Relays and replaces the Thermostat.

Source of the heating or cooling demand is the Intelligent Room Controller for HVAC. Which is used in every room with the connection of a Temperature Sensor and Damper.

All Room Controllers are combined in our Intelligent Temperature Controller to calculate the overall demand for heating or Cooling per furnace. Important to know is that one Intelligent Temperature Controller is responsible for heating, the other for cooling. You need to choose the right mode in the Properties of the function block.


In the above, you see the assignment of the controller.


With that set, the next step is choosing the HVAC Room Controller which connects to this Furnace. This could be all but it is likely that you have several Furnaces in your project where you need to know which room is feed from which Furnace.

With a double-click on the Intelligent Temperature Controller, the selection window opens.

In the above example, you can see that not all of the HVAC Room Controller are ticked and so if any of the ticked supplies a heating or cooling demand the HVAC will turn on.

Now you need to tell the HVAC Controller which Intelligent Temperature Controller it is responsible. Take the same steps as on the Intelligent Temperature Controller. With a double-click on the block, you open the selection window.

Above you see the selected Intelligent Temperature Controller which connects to the rooms supplied by this furnace. One is for heating and the other one for cooling demand.

That is showing the entire necessary setup for a single speed Gas Heating Furnace control. Please note that the HVAC Room Controller and HVAC Controller are still in development and in a BETA status.

Also note that a Furnace has a min. Airflow Threshold which the HVAC contractor can tell you. Change Parameter Str depending on the Threshold. At this stage, the HVAC can just turn on if the minimum Threshold of Str is reached for cooling or heating demand.

IMPORTANT: As the HVAC function is still in BETA status, please contact our support

team ([email protected]) to get the functionality and more detailed information.

You would have come across Room Size before when using Loxone Config. That is key for this heating/cooling demand, as larger rooms will have larger heating/cooling demands. This will affect your heating demand, which then affects your flow temperature, so it is crucial to get your room size correct.


Name FunctionExplanation
AIOutside TemperatureProvides Outside Temperature
IbBoost enables auxiliary heatingEnables boost heating
StStop the operationStops the operation
IIError inputStops the Controller if an Error is received from the Compressor for example
AUXAuxiliary heating InputTurns on the Auxiliary heater
IFInput FanTurns on just the Fan


QhDigital Output – HeatingTurns on Heating source
QcDigital Output – CoolingTurns on Cooling source
QfDigital Output – FanTurns on the Fan of the Furnace
Qh2Digital Output – Heating 2Turns on the second heating stage
Qc2Digital Output – Cooling 2Turns on the second cooling stage
Qh3Digital Output – Heating 3Turns on the Auxiliary heating source
QvDigital Output – ValveControls the Reversing Valve of the Heat Pump. (just available if parmater DT=0)
By default heating = off, cooling =on.  
AQeAnalog Output – Error CodeOutputs the Error Code


DTHeating Type0: Heat Pump / Electric

1: Oil / Gas

TcMinimum Runtime Minimum Runtime of the HVAC unit [min]
StrSwitch on ThresholdSwitch on threshold for heating or cooling to start the unit. [%]
TdvValve delayDelay [s] for the reversing valve to be in operating position
TbFan OverrunFan Overrun duration [s]; Overrun duration after heating or cooling was on
TonDuration for onMaximum duration for on [s]
ToffDuration for offDuration how long the system is off before it turns on again[s]
TmThreshold for Switching modeThreshold for switching the mode [%]
T2Delay for second stageDelay till second stage turns on [min]