Aprilaire 8336 - Manual (Page 2)

Features
• Multi Stage heating and cooling control.
• Zone system compatible as a master thermostat.
• Multi-Colored LED indicators for system status.
• Low battery indicator.
• Fahrenheit/Celsius display option.
• Adjustable from 45°F (4°C) to 90°F (32°C).
• Accuracy within ± 1 degree.
• Adjustable temperature differential: 1-3 degrees F.
• Automatic heating shutdown if temperature exceeds 90°F (32°C).
Replacing Existing Thermostat
1. Turn off power to heating and cooling system.
2. Remove cover of old thermostat to expose wires.
Do not disconnect wires. (Fig. 1)
3. Label wires per Table 1.
Table 1
Old Label New Label Description
R, V-VR or VR-R R 24 VAC, Return
Y, Y1 or M Y Stage 1 Cooling/Heating
Circuit
O or R O Reversing Valve,
(Cooling Mode)
B B Reversing Valve
(Heating Mode)
F or G G Fan control relay
Y2 Y2 2nd Stage Cooling
Circuit
W1 or W2 or W-U W2 2nd Stage Heating
Control
L or X L System Monitor LED
E E Emergency Heating
Circuit
C, X or B C 24 VAC, Transformer
Common Side
*NOTE: This thermostat requires a 24V common wire for proper operation.
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