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Anyway.. The "trunk lines" leading in/out of the boiler are getting
REAL hot.. No problem there. The gage on the front of the boiler reads
approx. 25 lbs. and 190-200 degrees F. This is probably above the
intended maximums of the system, as the relief valve is dripping. The
pump motor is turning, and presumably functional.

Is there a coupling between pump and motor? Could be the motor turning and
the pump is not.