I know this topic has been done to death over the years and I have searched the forum but still looking for an answer. Refers to the cabin heating on Ka (Mk1), Puma, Fiesta. After numerous HCV replacements and electrical testing I am now suspecting intermittent problems from the actual heater control. I know many people have replaced the control panel some with success, some without. I intend to buy another control panel from a breakers to try. Does anyone know if the little green printed circuit board containing that pesky problematic potentiometer can easily be removed from a breakers item and simply swapped over into my existing heater control panel? TIA

In the time I had my Puma, I changed it twice, but it was due to a fracture of the plastic pipe,not because it did not work.

IIRC the control uses pulse width modulation to control the valve, but if you try the Puma Forum https://www.projectpuma.com/ there might be more knowledge there,

Thanks Paulkp, the Puma site certainly has plenty of posts on this age old problem. Someone mentioned they “whipped out the old PCB” so it looks like it is an option. No heat in the Ka cabin in January needs to be addressed.