Home automation is the residential extension of building automation.
It is automation of the home, housework or household activity.
Home automation may include centralized control of lighting, HVAC (heating, ventilation and air conditioning), appliances, security locks of gates and doors and other systems, to provide improved convenience, comfort, energy efficiency and security.
Warning: Working with electricity can result in injury, property damage, or even death if it is not done properly. Please keep this in mind while assisting others. If you are not sure about what you are doing, hire a licensed professional.
The smaller one was poorly manufactured. It was whining. And now it's value is dead. What was it before? There was no value on heat shrink.
My advice if you don't want your house burning down. Dont fiddle with it, thow it away, or make an RMA claim.
It not like its a 100 Buck product. Saftey goes first here.
If you have decent experience in soldering, you can unsolder the coil, unwind at least the several top winds and rewind it again tighter and solder the wire end back to the terminal. If you want to completely replace the coil, you can use even a cheap tester like this https://www.ebay.at/itm/All-in-1-LCR-Component-Tester-TransistorDiode-Capacitance-ESR-Meter-Inducta/402624957700 to measure it (you have to remove the insulation on the end of the dangling wire). Then replace it with a similar coil.
If you have no experience with this or doesnt know anyone who does, just buy a new one as many recommended.