It is -10 degree outside. My thermostat is set to 76 degrees. It is only reading 73-74 degrees. The heat synbol is on thermostat to show heat is on, but radiator feels cool. Is this normal?

The forced hot water or steam is cooling off by the time it gets to the rads, depending on how far from the boiler and where the pipes run, such as along/up an outside wall. Be glad you are getting 73!