Thermostat using with LM319

This first circuit is designed by me to replace the mechanical switches used in some thermal Electric I have heaters.The electrical contacts to these mechanical thermal switches are always stoned and “no longer be trusted.”They could easily be welded together, the maintenance of these heating on full. It is definitely not good! Coarse adjustment of the temperature is a trimmer on the track, set to give a nominal range When using the fine adjustment.
It is quite difficult in a D-53, manufactured by NEC. The plumb line that is not isolated to the body of the thermistor is arranged. Why is it when you use the wire must be insulated to withstand the high temperatures such as fiberglass insulation against pipe.
Thermostat  Circuit Diagram:
Thermostat using with LM319-circuit-diagram
What is the size of the thermistor is the disk diameter 7 mm and a thickness of 2 mm. The end temperature control is a standard isolated potentiometer with a knob and / or good Protection against electric shock. Harter can be adjusted with this controller Auto-On and Off, “which automatically adjusts the room temperature.
The power control for the triac should be a 2 watt potentiometer with a knob isolated and / or Tree for protection against electric shock.  It can also be set up a 2-watt resistor on the circuit, an appropriate level of heat.“In general, full on,” how would the “Normal” setting when you use the contacts.On the chart, show me a 10 Meg resistance hysteresis. This may be of Lower Austria or higherdepending on how many degrees of difference between you and off cycles.Values between 100 K-ohms and 22 ohms, Meg are acceptable.