/diy/ - Do It Yourself

Can someone help me see what I'm doing wrong?
The thermistor is around 920 ohms at room temperature .
The voltage divider holds point A at 1.3V so the inverting input must be held the same.
So 1.3V across the 1K3 resistor is 1mA which goes through the thermistor dropping 0.92 volts and the 4k75 resistor dropping 4.75V so point B is approx 7V and point C is approx 2.25V.
I've verified these values in circuit and they match up.
So then, the 2nd op amp should try to keep the inputs matching so point D should be 2.25V too.
Then 2.25V dropped across the 3K4 resistor would give 0.617mA flowing through it
The drop of 7.75V across the 10K2 resistor would mean 0.759mA flowing through it
The difference of .142mA must therefore be flowing through the 25K5 resistor giving a voltage drop of 3.621.
The op amp is single supply so it can't go less than zero so it can't output -1.37V
Also when I actually measure the circuit, the op amp output is 0.6V and point D is actually a tiny bit higher than 2.25V at 2.32V.
I assume I have to take the resistors going to the alarm comparator and then ground into account but I'm not sure how