Source 1 S1-THEC11NS Thermostat

The York S1-THEC11NS is a commercial-grade, non-programmable digital thermostat designed for 1 heat / 1 cool configurations in residential and light commercial applications. This low-voltage control is engineered for compatibility with conventional single-stage gas or electric furnaces, air conditioners, and millivolt heating systems. As a veteran-preferred HVAC replacement part, it offers a reliable digital upgrade for older mechanical mercury-bulb thermostats, ensuring more precise temperature regulation without the complexity of scheduling. The unit features dual power options, functioning via 24VAC hardwiring or 2 AA alkaline batteries, providing flexibility for 4-wire or 5-wire installations. Its intuitive interface includes a clear LCD screen, dedicated "COOLER" and "WARMER" buttons, and a front-loading battery door for rapid field servicing. The S1-THEC11NS wiring is straightforward, utilizing standard terminal designations (R, C, W, Y, G) with factory-installed jumpers for single or dual transformer systems, making it a robust solution for maintaining stable environmental control in diverse HVAC environments.

• Universal System Compatibility: Operates seamlessly with 1H/1C conventional gas, electric, and oil systems, as well as millivolt applications and single-stage heat pumps without auxiliary heat.
• Flexible Powering Options: Can be powered by 24V low-voltage wiring for a permanent connection or by two AA batteries for systems without a common (C) wire.
• User-Friendly Interface: Features a large, backlit digital display for easy reading in low-light utility rooms or dark hallways.
• Maintenance-Focused Design: Includes a front-access battery compartment and a low-battery indicator to prevent system downtime during extreme weather.
• Precise Temperature Control: Replaces inaccurate mechanical levers with a digital thermistor for tighter temperature swings and improved equipment efficiency.

Is the York S1-THEC11NS compatible with my 2-wire heating system?
Yes, this unit is an excellent choice for 2-wire, heat-only systems, including gas-fired wall heaters and millivolt floor furnaces, when operated on battery power.

Does this thermostat require a common wire (C-wire) for installation?
A common wire is recommended for constant power, but it is not required. You can utilize 2 AA alkaline batteries to power the logic circuit if a C-wire is not present at the mounting location.

Can I use this thermostat for a heat pump with emergency heat?
No, the S1-THEC11NS thermostat is specifically designed for 1-stage heating and cooling. For systems requiring auxiliary or emergency heat (multi-stage), a 2H/1C or 2H/2C model is required.

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.