I have been through 3 different 180 degree thermostats, and I have yet to get one to open. What other reason, besides a bad thermostat, would cause it not to open? I have run the temp up to 195 degrees and I am positive it is installed properly. The fan kicks on around 175 and stays on, while hoses look as if they are going to burst. I am running a Koyo half-size on a built B18C. Any help would be greatly appreciated, i am tired of changing the bastard out.

 

Up for ideas.