hi,
It looks as though you are using the diode as a temperature measuring sensor???
Where did you get the circuit design from?
Also I dont see any decoupling on your circuit diagram, I appreciate you are using a 9V PP3 battery, but these batteries do have a 'high-ish' internal resistance.
The 7106 will generate some electrical noise on the power rails and you have the sensor diode and Vref/offset connected to that rail.
Connect a 47uF and a 0.1uF capacitor across the power rails.
Have you measured the 9V battery voltage when the circuit is connected.?