Help! heater controls

[mutley]

Hi. My heater controls are not working properly . temperature will go up but not down i think there is a problem with the switch is there a quick fix ? pull it out and clean the switch ? or will i need a whole new heater control unit ? have you guys come across this before is it common ?

 

[boomdriver]

try cleaning....if its opt - 68 it may need servicing.

 

[mutley]

try cleaning....if its opt - 68 it may need servicing.

thanks Boomdriver , that will be my first option hopefully it will work.