AC Control Air for Daikin S21

Loxone AC Control Air is a compact interface module for integrating air conditioning units.

For this purpose, a suitable product variant for supported air conditioning systems must be selected.

The different variants vary in the interface used, the connecting cable and the firmware. The AC Control Air takes over the control of the air conditioning in a Loxone installation instead of a conventional remote control.

Datasheet AC Control Air for Daikin S21

Table of Contents


First switch off the air conditioner and then disconnect the mains power supply.

For installation, you need access to electrical connections in the indoor unit of the air conditioner. Refer to the installation or service manual for the air conditioner you are using to determine how to remove the covers and where the various terminals and connectors are located.

On the circuit board of the Daikin indoor unit, locate the S21 connector for the wired remote control. If a remote control is connected here, it must be unplugged and can no longer be used.

Make sure that the connector matches the connector of the enclosed cable of the AC Control Air in number of poles and shape. Then plug in the AC Control Air with the connecting cable:

In some air conditioners, the S21 connector on the circuit board is in a smaller format. In this case, the AC Control Air is connected to a short adapter cable (EKRS21), which is often already plugged in on the circuit board of the indoor unit. If not, the EKRS21 adapter cable is available from Daikin:

Some air conditioners are not equipped with an S21 connector. In this case, an additional adapter board (KRP980B1 or KRP067A41 depending on AC unit type) from Daikin is required, which provides the S21 connector:

Fasten the AC Control Air to a suitable place in the device, e.g. with a cable tie.
Make sure that the device cannot come into contact with mains voltage, hot, cold or moving components, or moisture.

For best reception, the AC Control Air has to be placed outside of metal covers. The supplied connecting cable must not be extended.

Finally, reinstall the housing covers and turn on the mains supply and the air conditioner.
The AC Control Air is now supplied with voltage from the air conditioner and can be paired in the next step.


In delivery state, pairing mode will be active after the power supply has been established. This is indicated by the status LED flashing red/green/orange.

Then follow the pairing procedure

To activate the pairing mode manually, switch off the power for 10 seconds, then switch it back on. If no connection to a Miniserver can be established for five minutes, pairing mode will be activated for a limited time.


Loxone AC Control Air is programmed and set up using the AC Control function block in Loxone Config:


In case the communication with an air conditioner does not work (correctly), a diagnostic analysis can be started in the context menu of an AC Control Air. This enables communication data to be displayed and recorded:


Summary Description
API Connector Intelligent API based connector.
API Commands

Diagnostic Inputs

Summary Unit Value Range
Online Status AC Control Air Digital 0/1


Summary Description Default Value
Monitor Online Status When selected, you will be notified via System Status or the Mailer if the device is no longer available or goes offline. -
Serial Number Serial number of the Air device -
Device type Air device type -

Safety Instructions

Installation must be carried out by a qualified electrician in accordance with the applicable regulations.

This device must not be used as part of safety-critical systems.


Datasheet AC Control Air for Daikin S21