Carrier HH22UC033 T-Stat

The Carrier HH22UC033 is a heavy-duty single pole double throw (SPDT) thermostat designed for high-voltage HVAC applications requiring precise defrost termination or temperature control. Specifically engineered for 240V and 277V circuits, this bimetal snap-action switch features fixed setpoints with an open at 15°F and a close at 35°F. This specific calibration ensures reliable cycle management in commercial refrigeration and air conditioning systems where environmental conditions demand consistent performance. Its rugged construction facilitates long-term durability in high-demand industrial environments, providing an exact OEM replacement for failing disc-type thermostats in Carrier, Bryant, and Day & Night units.

Key Benefits for Technicians

• High Voltage Compatibility: Rated for 240/277V applications, eliminating the need for step-down transformers in commercial control circuits.
• SPDT Switch Configuration: Offers versatile wiring options for both heating and cooling logic or signaling auxiliary components.
• Precision Calibration: Fixed 15°F open and 35°F close points prevent short cycling and ensure accurate defrost termination.
• OEM Fitment: Direct replacement part ensures terminal spacing and mounting flange alignment match factory specifications.

Common Technical Questions

What is the primary function of the HH22UC033 in a heat pump system?
This defrost thermostat monitors coil temperature to terminate the defrost cycle once the ice has melted, switching the system back to heating mode when the 35°F setpoint is reached.

Can this SPDT control be used for both NO and NC applications?
Yes, the SPDT contact arrangement allows you to utilize the common terminal with either the normally open or normally closed lead depending on the specific wiring diagram requirements of the air handler or condenser.

Is this part compatible with non-Carrier branded equipment?
While designed as a Carrier OEM replacement part, it can be used in any application requiring a 277V SPDT disc thermostat with a 15/35 degree operating range, provided the mounting footprint is compatible.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.