I re-did my bathroom about 5 years back, and the kitchen immediately below the bathroom 2 years ago.

Everything has been fine for years. Good pressure both hot and cold.

My tub is a clawfoot with a newer Porcher tub filler. 2 Dahl mini-ball finishing valves are stubbed out from the wall for the supply to the tub.

The other night, wife goes to run a bath and no hot water. I go in, turn on the hot, and it works. Chalk it up to the Fonz effect I seem to have on anything she says doesn't work (ranging from the TV to the computer to the water).

Next night, she goes to do the same, and nothing. Not a drop.

So - clearly it must be the cartridge. I decide to step past that and go straight to the mini-ball valve. Disconnect the braided supply line from the mini-ball valve (after turning it off) and slowly open it up. Nothing!

Now of course I think it's the valve. I happen to have a thin piece of copper wire - fish it through the open valve and it passes easily. Today, I turned off the hot water and removed the compression fit valve. Just a copper stub sticking out of the wall. Turn the water back on, and NOTHING. Not a drip, not a hint of moisture coming out.

There is hot water everywhere else, including the shower which branches off this supply in the floor. Hot water in the laundry, next to the bath. Everywhere but the bathtub.

The copper plumbing in this house is perhaps 15-20 years old at most. Anyone have any insight into how a 1/2" soldered copper line gets clogged, and not just partially, but completely, what must be within a couple feet of the stub out of the wall? Any further back and it would effect the shower as well.

I'm at a loss, and have little interest in opening up walls or tearing up 80 sq ft of heated marble floor that is only 5 years old.

There's a 90 elbow about 8 inches in from the wall, and no obstructions to that point. I don't have anything flexible yet stiff enough to fish further into the copper line.

The bathroom from 2008 when I finished it: