Black & Decker BDXCTSH1 Installation & Operation Manual page 25

APPENDIX A – SCHEMATIC WIRING
Failure to correctly wire the BDXCTSH1 Thermostat could
WARNING:
result in death or serious injury. The local jurisdiction may
require installation by authorized service personnel.
Conventional Boiler / AC (Non-Heat Pump) – 2 Transformers
A-2