Daikin-McQuay 668375301 Thermostat

The Daikin-McQuay 668375301 is a high-performance 7-day programmable thermostat engineered for 2-stage heating and 2-stage cooling applications. Designed specifically for integration with McQuay and Daikin water source heat pumps (WSHP) and rooftop units, this digital controller ensures precise temperature regulation and energy efficiency through its multi-stage logic. It features a large backlit display for clear visibility in mechanical rooms and includes a dedicated mounting plate for a clean installation over standard junction boxes. The unit supports dual fuel configurations and provides specialized terminals for remote sensor integration and auxiliary heat control. As a direct OEM replacement part, it maintains factory specifications for fan cycle control and compressor protection intervals, ensuring the HVAC system operates within its engineered parameters while reducing unnecessary cycling and wear on the refrigeration circuit.

• Multi-Stage Control: Manages 2H/2C stages to optimize compressor staging and liquid line solenoid operation.
• Enhanced Programming: Full 7-day scheduling allows for precise occupied and unoccupied setpoints in commercial environments.
• OEM Compatibility: Precision-matched for Daikin-McQuay heat pumps, eliminating communication errors common with universal stat alternatives.
• System Protection: Built-in delays and logic sequences to prevent short-cycling and protect HVAC compressors.

Does this thermostat support remote sensing?
Yes, the 668375301 features terminals designed to interface with 10k ohm NTC remote sensors for averaged or remote-area temperature monitoring.

Is this unit compatible with heat pump systems?
This controller is specifically designed for multi-stage heat pumps, providing the necessary changeover valve control and auxiliary heat sequencing.

What power source does this thermostat require?
The unit typically operates on 24VAC common power supplied directly from the HVAC control transformer.

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.