Here in Wisconsin we hit a low of -18 and the system finally hit the point where it couldn't keep up. I got up this morning and the desired temp of 75 on the first floor was not held (we had dropped to 73). The short story and question is: Specific details: Zone 1 (1st floor) Making a call for stage 3 heat Zone 2 (2nd floor) Making a call for stage 1 heat First floor setpoint 75, actual temp 73 2nd floor setpoint 70, actual temp 70 I found that if I made a call for 2nd stage heat on the 2nd floor THEN the zone unit would make an emergency heat call. It would seem that something is configured wrong on the zone unit. I don't see many settings that might impact this. The zone unit has the zone percentage settings and currently both the 2nd floor and the 1st floor are set the same at 70%. Anyone have ideas? Is this a configuration issue or is the zone unit defective or is this the expected behavior (which I wouldn't expect since it means that a zone would drop below the desired set point). Ok, the software engineer in me is digging deep into the intellizone install manual. It discusses staging options. It is currently set to Normal (as shipped). I see it talks about Faster with timer which leads me to believe that if I select this staging option it might engage the electric heat if only one zone needs it. However, the documentation puts in bold that this be avoided. Anyone have details on the exact operation behaviors for the various staging operations?