A few weeks ago I had a new stat fitted to my 2.5 petrol 90

Yesterday while I was out the temp guage never moved. The top hose was warm but the bottom hose was cold.

Had new coolant when the stat was done last time.

Could it be the stat again or something else ?

Hi, it could be or a blocked rad. try taking the stat out and see if the temp goes up-drop the stat in a pan of boiling water to see if it opens.
James