why is the line for the hot water coming from the boiler not hot, but the return line is hot, already changed the circulator pump,and drained the system, but still not getting hot water to circulate ?
Recheck the rotation of the pump. some systems usually pump the return into the boiler and the supply is leaving on the other side. When changing a pump, or opening the system ...the pumps prime can be lost. Find a way to vent air out of the volute of the pump after you check for proper rotation. Start and stop the pump and listen for air bubbles. Also check the ampere draw on the pump. if its rated for example 6.6 amperes, then a pump that is doing its job pumping will be pulling close to or somewhere near the 6.6 it is rated at or (Full Load Amperes.)
