Not an answer as such, but I'm wondering if it might do. We have a humming when the boiler isn't operating and when the Magnaclean unit is very hot to the touch.
1999 Mercury front and humming noises can because by several things. Tire noises are the most common cause. A tire that is not wearing properly can cause a humming noise.
yes it would
the bearings
Possibly worn wheel bearings can create a humming or groaning sound.
Wheel bearing is on its way out.
The heating system and every other part of the home is included. The main thing is what caused the damage. If it is a covered cause it will be paid for and if not it will not.
One would really have to hear it in order to determine for certain. Are there any particular conditions existing in which the humming occurs? Wheel bearings are a possibility.
bad wheel bearings
You may need differential fluid...check that.
Certain types of tires may cause a brief humming noise after your initial acceleration. The transmission may also cause a brief humming noise.
Check the condition of your heater core.
Wheel bearing?