The Model 6404 or 6403 Zone Panel can be configured to control heat pump
or conventional applications. The Model 6403 can control up to 3 zones. The
6404 can control up to 4 zones and is expandable up to 12 with the use of
the Model 6401 two-zone expansion panel. The features include:
- 2 heating and two 2 cooling stages (conventional)
- 4 heating and 2 cooling stages (heat pump)
- Integrated balance point control
- Equipment protection