Everything Taco is what this page is all about. Learn to make repairs and even replace your Taco Pump.
I hear the pump on but the heaters not getting hot. Could there be a clog somewhere? Help
Your system is most likely air locked. The pump cannot move air. Purging the system of air will be required to make the zone work. The cause of the air getting in must be fixed first. Two ways air can get into a system are from a leak which may only be noticed when the system is cold. Or air can get in from the thermal expansion tank blowing the diaphragm and releasing the air into the pipes. I have some e-books on Amazon you'll find if you search Robert VanNorden there. Hope all that helps.