Rambling explanation of how I recently repaired the boiler after having chronic annoying noise/vibration in the system...apparently. caused by the replacement electric motor. The pump had always been a B&G Series 100. After some internet searching I elected to try a Grundfos Brute 3 speed pump. The amazing result is ABSOLUTE QUIET in the system. Of course the real test will be in January. Meanwhile, I decided to replace other components and learned a very old Pressure Reducing Valve was faulty as well as a pressure gauge. The gauge reads 10#s higher than actual pressure.