DatoEE is never defined
i see that no data is stored to eeprom therefore tmax and tmin = 255

then --
Code:
If temperature > Tmax then
PORTA.6=1
Endif
why would porta.6 change if temperature < Tmax your code only sets the pin it never clears it
the initial state of pin should also be set , there is no code visible to set trisb either

Code:
If temperature > Tmax then
PORTA.6=1
else
PORTA.6=0
Endif

this makes me wonder what your actual fosc is , you posted no config section and there is no OSC definition
Code:
PAUSE 50 ' Wait 1/4 seconds per reading