Thanks for comments. Found a photo on internet that confirmed top is just 'prise off' and was then able to free motor. Valve working OK now.
Not sure where you can get these for £20 - cheapest I've seen on e-bay is £24 + 6 delivery (£30).
Cheers ...
Hello ... (first post so excuse errors, etc).
I have a Rondostat HR20 displaying the E3 error code (motor cannot be moved). Has anyone come across this problem? Is there an easy fix for un-jamming the motor? Failing something simple - has anyone managed to dis-assemble one of these to get...