The actuator remains closed, does not allow the pin to move upwards anymore

We are slowly but surely getting desperate. It was supposed to be a simple replacement of a faulty actuator. So we bought a new actuator, replaced the old one with it, and connected the blue and brown cables. As soon as we now attach the new actuator, it pushes the pin all the way down, preventing the flow. Although the two cables are connected correctly, the actuator no longer lets the pin move up; the blue part on the actuator is not visible.

We are now asking ourselves for what reasons.

Audi or VW?
Jokes aside, of course it's about the heating :)

Have you ever called in a professional?

Regards

We initially wanted to avoid that. The system is two years old, was newly installed.

We wanted to avoid that at first. The system is two years old, was newly installed.

Then is there still a warranty on it?

Okay, the system is 2 years and 5 months old. Warranty expired, no goodwill gesture.

Just a suspicion: There are actuator drives that operate "de-energized open" and there are some that operate "de-energized closed". Since you write that it closes, I think you bought an actuator that closes when energized, meaning it is de-energized open. Maybe this is where the mistake lies?