I have the solution, finally after looking for 2 days.
First off, I couldn't quite put it all together based on what I was reading. I finally tracked down the Fahrenheat web site (www.fahrenheatpro.com
). And called tech support (800) 452-4179.
To wire 2 BB units to 1 tstat.
1. Use #14 wire for 0-12 amps, #12 wire for 12.1 to 16 amps and #10 wire for 16.1 to 24 amps.
2. I have a 12/2 wire going from the tstat to BB#1 and another 12/2 wire going from BB1 to BB2.
3. Onthe left side of the heater, you will have 2 sets of black wires tied together with a nut (on right side it's 2 sets of Black/Red wires). You can use either side of the heater. For the purpose of explaining this, lets use the left side, 2 sets of black wires.
4. Undo one of the sets of black wires (it doesn't matter witch), the other set will be left alone.
5. Take the black wire coming from the tstat and tie it into one of the black wires from the heater and the black wire going to the second BB unit. So you will have those 3 wires tied together with a nut at the 1st BB unit.
6. Take the white wire coming from the tstat and tie it into the other black wire from the heater and the white wire going to the other BB heater. Again, you will have 3 wire tied together here.
7. At the second BB unit, tie the black wire coming from the 1st unit to one of the black wires in one of those 2 sets of black wires. Again, only undo 1 set of wires at the 2nd unit, leave the other one alone. Tie the white wire coming from the 1st unit to the other black wire.
8. Make sure ground wire in grounded at the tstat and at both BB units.
Hope this helps...... If I was less clear than I hoped, call tech support and they will walk you thru it....