Newbie: Sugar wash has no alcohol

[PIDnerd]

To break in my newly built 2" Bokabob still, I made up a wash using table sugar following a recipe posted by wineo. Followed it exactly except for the substitution of potassium metabisulphite for DAP (the store didn't sell it).
8 # sugar, 6 gal water, 1 tsp citric acid, 1/4 tsp gypsum, 1 tsp potassium metabisulphate. At 90 degrees, spread 1/4 cup of distiller's yeast, closed up the fermentation bucket & filled the airlock. Left the bucket in my guest bathroom tub for 2 weeks. It bubbled strongly for the first week, then tapered off. After 2 weeks, took off the lid & put in the hygrometer - it said 0% alcohol. To test the device, put it in some commercial hootch; read 90 proof as labeled. The wash does smell like it did at the Jack Daniels brewery I toured last month.
This morning, put it in the boiler & set the temp for 183 degrees. The boiler hit that in 50 minutes, but after 2 hours, the upper column is room temperature. I'm assuming that's because there's no alcohol vapor to rise. My plan is to let it run for another 2 hours. surely a proper wash would be producing by then.
So my question is: why didn't the wash ferment? Was the subsitution a mistake? Should the wash be kept at 80 or 90 degrees? Does table sugar not ferment? (MY questions about operating the still will be posted elsewhere).
Thanks in advance.