Battery powered, low voltage electronic setback heating and cooling thermostat with sealed relay contacts. Pre-programmed with four adjustable heating and cooling periods for weekdays. Preprogrammed with four adjustable heating programs and four adjustable cooling programs for weekends.

Features:
-2 heat / 1 cool heat pump
-Energy Star compliant
-Separate programs for weekdays and weekends
-Preprogrammed - up to 4 programs per day
-Separate programs for heating and cooling
-Either system powered with battery backup or battery powered
-Easily reprogrammed with LUX Programming Dial
-Large Liquid crystal display
-5 minute air conditioning compressor delay
-Temporary and constant temperature override
-Total isolation between system power and thermostat

Compatible With:
-1 or 2 stage heat / 1 stage cool heat pumps
-Single stage heat pumps
-24 Vac (max)

Non Compatible With:
-Multi-stage gas or oil furnaces
-3 wire hydronic systems
-Millivolt systems

PSSH521 Detailed Specifications
Dimensions: 4-3/4" wide x 3-3/4" tall x 1-1/4" deep.
Electrical Ratings: 1-1/2 AMPS at 24v AC. 2 "AA" batteries included.
Temperature Differential: + or - 1o factory preset differential adjustable from 1/4oF to 2-1/4oF.
Temperature Control Range: 45oF to 90oF (7oC to 32oC) - Celsius and 12/24 hour time capable.
Compatibilities: 1 or 2 stage heat pumps with 1 stage cooling. 24 Vac systems.
Terminals: G, Y, W2, E, B, O, R, C.