Greetings all, I have a OWB connected to a presurized system with cast iron radiators. I have the boiler running to the heat exchanger, then to the presurized system. My water temp coming into the exchanger is 170, but I am not gettting the water over 130 at the radiators. Everything is new, put in this fall. I use to get 170 at the radiators, no problem. Could it be my pump is not putting out enough flow or is it more likely I have a clogged heat exchanger? The pressure stays at 20 lbs, and I have no air in the radiators. I have noticed that I seem to be overheating (lots of steam out of the overflow) at the boiler more often. I guess I could change out the pump first, but thought I would ask the experts if there was an easier way to determine which is causing the problem. The water going in top the exchanger is hot, but the return is just warm. Thanks