Programming the STC

I'm down to the finals on setting up my homebuilt Electro-Brewery. I've been watching your video on programming the STC (yours was for a fridge, mine is for hot brewpots). when I turn on the power to the control center, I get that annoying beep whether the sensor is plugged in or not. It will only stop if I turn off the power at the STC; also, I get no flashing light to tell me to wait until it's ready to program. Other than that, no matter how long I hold down the 'S' button, I get no 'F-1' or any other from the readout, only the 'EE'.
I've checked the power to the STC with my multimeter, and it reads 120V. (I bought STC's that will use 120/240, as I need a 120V output for the coil on the mechanical relays) - Solid state was out of my budget.
I've also confirmed that there is 240V to the hot side of the relay, which, after the coil would activate the magnet, would send 240V to the heating elements. Trouble is, I get no output from the STC because I haven't been able to program it.
I don't know if I got a bum STC or not, so I'll wait for a comment from you before I make a decision to buy another or not. They take a month to a month and a half to get here by turtle-sled - (even dogsled would be faster!) - from China, and we're going to be out of state for a few weeks, so I would have to see if I can buy one at an electronics store for double the price of ordering from China.
TIA for any advice/comments.