Armstrong Furnace ASTAT503-1 Outdoor Thermostat

The Armstrong Furnace ASTAT503-1 Outdoor Thermostat is a critical OEM replacement part designed to optimize the performance of heat pump applications and split system enhanced heat pumps. Engineered for outdoor temperature sensing, this device features an electrical rating of 120/240V, 5 full-load amps, and 20-lock rotor amps, ensuring robust operation in demanding environments. By monitoring ambient air, the ASTAT503-1 accurately manages the transition between heat pump and auxiliary heating stages based on a user-defined setpoint. This HVAC control sensor is compatible with the ASTATBOX502-1 mounting box and can be integrated with the AFOSL500-1 fossil fuel kit for seamless operation in dual-fuel heating systems. As a genuine Armstrong Air part, it provides precise ambient temperature monitoring to help prevent equipment strain and maintain energy efficiency during colder cycles. Its durable, weather-resistant design ensures long-term reliability for residential and light commercial outdoor HVAC controls.

• Optimized Efficiency: Accurate sensing prevents unnecessary heat pump operation during extreme cold, improving overall system longevity.
• Dual-Fuel Compatibility: Works seamlessly with fossil fuel kits to manage transitions between electric and gas heating sources.
• Versatile Installation: Can be mounted in a dedicated exterior box or directly within the unit's compressor compartment.
• OEM Precision: Genuine Armstrong Furnace component ensures exact fit and electrical compatibility with existing wiring.

Is the ASTAT503-1 compatible with other brands?
While primarily designed for Armstrong and Ducane equipment, it functions as a standard 120/240V outdoor thermostat; however, we recommend verifying specific wiring diagrams for your model.

Where is the best location to install this thermostat?
For the most accurate outdoor temperature sensing, it should be installed in a shaded area away from direct sunlight or the warm exhaust air of the condenser.

Can I use this to control a fossil fuel furnace?
Yes, when paired with the proper fossil fuel kit (like the AFOSL500-1), it acts as the changeover switch to engage the furnace when temperatures drop below the heat pump's balance point.

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.