"New Attic Fan Controlled By Thermostat" At least that is what the features list said.
And it was true. There was a new attic fan and it was controlled by a new thermostat.
I see so many things when looking at this wiring.
First, all of the wiring used for this new appliance is old. Who knows how long the other attic fan was that needed to be replaced. Let's assume 20 years. It may have been much older!
And who knows if that one was wired correctly!
But this one is not.
- New wiring for new appliances in an older house is always a good idea. Newer appliances heat up a bit more than older ones and sometimes that heat cannot be handled efficiently by older wiring. And, an attic space gets hot and you don't want any wiring to overheat in addition, particularly older stuff!
- The house was built in 1962. The old BX cable that used to service the older fan now services the new attic fan. That's the cable wrapped in metal. It is not grounded as this old cable came without one. The ground wire than came with the fan is hanging up there beside motor in the unit.
- The gray cable is what brings power to the connection inside the panel box. It is connected to a light fixture in the hallway ceiling below and looks too small to contain a ground cable. I did not go into the box, but the screws were very old, and looked undisturbed, and I suspect nothing was done to the connections in there because
- the old cable now attached to the new thermostat had the insulation improperly stripped for some reason to connect the cables OUTSIDE the thermostat box.
- The ground screw on the thermostat was not utilized.
COMPLETE GROUNDING IS VERY IMPORTANT FOR AN ALUMINUM APPLIANCE SITTING ON A ROOF! IT IS QUITE SUBJECT TO LIGHTENING STRIKES!!
All of this would say what? That a friend, Uncle Bob or handyman, none of whom are electricians, wired up the "new fan controlled by thermostat." This whole assembly needs professional attention.
My recommendation: when the features list on any house mentions this or that new installation, check them out completely. Make certain these things were done professionally. And hiring a home inspector to have a look is an exceptionally good idea!
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560