A421 Series Electronic Temperature Controller -40 to 212 Degrees Fahrenheit, SPDT Single-Pole Double-Throw Relay, Direct Replacement for A419Abc-1C, Single-Stage HVAC Thermostat Controller, Pro-Grade Durable Performance
✔️ Direct replacement for A419Abc-1C with SPDT single-stage control
The A421 Series Electronic Temperature Controller is a single-stage HVAC device designed to regulate heating and cooling by switching a relay on and off. It serves as a direct replacement for older models and is built for reliable, pro-grade performance in commercial or residential climate control applications.
✅ Single-stage controls
✅ SPDT output relay
✅ Temperature range -40 to 212°F (-40 to 100°C)
✅ Direct replacement for A419Abc-1C
✅ Bright backlit LCD with adjustable brightness
✅ Three-button touchpad interface
✅ LED indicates relay status
✅ Anti-short cycle delay adjustable
✅ Temperature setback and sensor offset
✅ Made in United States; Johnson Controls
💡 What is an electronic temperature controller used for in HVAC systems? These handy devices help maintain comfort and efficiency.
- Controls heating and cooling by energizing relays at setpoints.
- Handy for precise climate control in homes and small offices.
- Improves energy efficiency by reducing overshoot and cycling.