I'd go straight to www.showerdoc.com. look here:
https://www.showerdoc.com/shower-spares/redring
Scroll down till you find your exact model and click through.
Scroll down and you should find a list of model-specific FAQs that will very likely cover your problem.
If not, send them a question yourself.
For what it's worth, it sounds to me like the overheat cutout is faulty and needs replacing. Showerdoc will be able to help more.
Rtkfvfj
January 2025