And we recently had a post from an indy shop in Puerto Rico with same problem - new aftermarket stat would not open.

 

Follow up.... Removed thermostat and took it back to dealer. Explained what the issue was and they thought I might have the hoses backwards. Plus I complained that the new hose from the water pump seems too close to the pulley and might rub. They humored me with a new stat. Installed and good and bad news. Not running hot. 195 on freeway. 200 in city traffic. Have water in dash. It's was 40 outside and no white smoke from tailpipe. Will try bleeding again and watch level for a week. Then test coolant for exhaust fumes. Thanks all for your help.

 

IMHO you just have air bubble to be chased out by whatever method works best. Thanks for the update.

 

Good to hear. Sounds like another bad stat. Geez. And yes, just bleed the system and you should hopefully be good.