Heater heat

If you dont know what temp the thermostat is then its probably time to replace it Rani.

Test the new one in a pot of water with a cooking thermometer as outlined before, some new ones are bad out the box.

If its below 50* I wouldn't hesitate getting a 205 thermostat, just make sure when the 50's come back you install a 195 (oem calls for 195).