Yes, Sylvan. I understand your reason for assuming that this person’s house has a Johnson controller with master and sub master stations or the Good OLE Leslie steam stations. New York City homes are often over 5000 square feet built before insulation was fashionable and may have these devices.
At the moment, we don’t know what this person has, so it is a best guess. Does the ‘termostatic valve’ have a plastic cover? Did Sylvan guess correctly? If the person has a balancing valve of some sort before the valve, he may reduce the noise by reducing the flow rate.
Will opening the valve adjust the heat in the loop or the room? Or will it make the rooms overheat? Tune in for the next installment.