heating actuator MTN6730-0001reset issue

[IC_Systems]

Hello dears,

I am encountering an unusual issue in an older project where the customer has reported that the underfloor heating (UFH) system is not functioning properly. Upon investigation, I observed that the heating actuator has been reset to its default individual address, which is 1.1.255. Strikingly, this issue affects three out of the four devices.

I am exploring potential causes for this unexpected behavior. Could it be related to a power failure?

Thank you for your attention to this matter.

Best regards,

[Heribert_Dölger]

Hello

Could be the result of electromagnetical interferences most probably coming from loads installed close to the actuator. Such interferences can have an impact on KNX devices when single bus wires are laid close to single mains wires. You have to keep a minimum distance of 4mm. Such wiring problems are typical for such described errors.

Such interference also can come from inductive loads. So would be interesting to know what kind of loads are connected to the actuator.

If that does not help please provide pictures of the installation of the devices, wiring, connections, switchboard etc.

Best regards

[IC_Systems]

Hello @Heribert_Dölger 

the load connected to the actuator is normal valve actuator 220V.

the site is running well for about 5years with same panel structure and devices!

is there another way for factory reset from the front buttons?

[Heribert_Dölger · Accepted solution]

Dear Khalil

The device has no option to set it back to factory default settings, neither by the buttons on the front nor by software function.

Only option could be "unload" command from ETS but this would set the individual address to 15.15.255, not 1.1.255.

[IC_Systems]

Thank you @Heribert_Dölger  for the valuable information, I might be wrong regarding the address after issue it might be as you said 15.15.255.