No heat

I just changed the thermostat, because I had very little heat, and the temperature gauge stayed at 0. Once I changed the thermostat, the heater worked awesome, and the temperature gauge goes to around 215. The heater only worked for a couple days, on the third day, it overheated and stayed stranded on my way to work with no heat. I do not know what it could be. Can you please help?


This is the thermostat, I took off car when I had very little heat.