Did you clean the filter at the pump if there is one? Also take a picture of this boiler room, if that's not a problem. As for the picture, it should be warm, especially since there is a pump. If there are valves, you can unscrew the pump motor from the body with allen and check if the impeller is melted or clogged. If there is a differential valve, check by hearing if you hear such a thump when you turn on the pump.
