LUX PSDH121 non-programmable thermostat matches most 24V 1 or 2-stage heat and 1-stage cool heat pumps.
We name the system, the voltage, and the wire. It mounts horizontal or vertical with an easy-view backlight. The emergency-heat switch keeps warmth during faults.
PSDH121 Highlights
Heat Pump Focus
Runs 1 or 2-stage heat with 1-stage cool without programming.
Emergency Heat Switch
Forces backup heat when the pump cannot keep up.
Adjustable Compressor Delay
Protects the outdoor unit from short cycling.
9-Step Swing
Fine-tunes on-off differential for comfort.
Low Battery Indicator
Warns before power loss.
PSDH121 Specifications
Power: Dual powered, 2AA alkaline batteries included
Display: Backlit, Fahrenheit or Celsius
Mounting: Horizontal or vertical
Compatibility: 24V heat pump systems 1 or 2-stage heat / 1-stage cool
Not compatible: Multi-stage gas or oil furnaces, hydronic hot water, 120V/240V line voltage, conventional non-heat pump systems
Control features: Adjustable compressor delay, temperature calibration, high/low limits
