Siemens Thermostat Knob is very Stiff - Can it be Loosened? Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[daveplum]

I have a Siemens thermostat on which the temperature selector knob is extremely stiff. It seems to be the same model as the one at
http://www.heatingspares247.com/siemens-room-thermostat-raa20-gb.html
Is the stiffness by design or, if not, is there any way of adjusting it. I cannot see a way of opening it op.