K8009 temperature

Hi , i have this clock for several years now , and recently took it back in service (thanks to this forum :stuck_out_tongue: ) by manual operation with 2 switches .( because of RF interference )
my question : the temperature reading is not very accurate and hard to adjust ( i have changed rv1 for a multiturn type )
the temperature reading at 21 C is about 24 C and at 16 C about 8 C . the sensor is 4mm outside the housing and i bought this clock as a built kit.

hope you can help.


Hard to tell what is wrong without being able to examine your circuit.
Is the power supply OK? Resistor values correct? Correct op-amp? No bad solderings or other mechanical problems?
We can still service the item, if it is returned.