I have two of these Siemens RDE 20.1 thermostats for underfloor heating at our place. unfortunately the previous occupants removed and discarded the battery holder so underfloor heating was out of action. I tried to look up where I could buy spare parts but I think the product is end of life already so no support... :( I decided to do a small design for a battery holder without having the original part to solve this problem.
To make my life easier I bought a pack of led lights in two dollar shop having AAA size battery holder so I could get out and reuse the battery connection pads with string :)
I also bought some office pins in the two dollar shop you can see on the photo and used that to make up the connector part to the thermostat unit...
So at the end after printing I just had to remove the print support material and clean the part and insert the pads and connector and Voila the thermostat is back in action....
The holder also has a small handle
- to pull the battery case out
- and also to unlock the small springy lock