Thermostat Features - Aprilaire 8400 Series Safety & Installation Instructions

THERMOSTAT FEATURES

ALL 8400 SERIES THERMOSTATS
• Large, clear, backlit display is easy to read – even
in the dark .
• Displays room temperature, temperature setting, and
optional outdoor temperature .
• Dual power option (Battery or 24 VAC) .
• Front battery door access for fast, easy replacement .
• Built in compressor protection .
• Circulation fan mode for air cleaning .
• Water panel, dehumidifier, air filter, and HVAC
service indicators .
• System test mode .
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PROGRAMMABLE MODELS ONLY
(8463, 8465, 8466)
• Separately programmable weekday/weekend
schedules .
• Easy to use temperature control can override
program schedule at any time .
• Progressive recovery . Progressive Recovery feature
allows the thermostat to activate the heating and
cooling equipment prior to an event in order to reach
the desired temperature at the start of the next
scheduled event .
TROUBLESHOOTING
DISPLAY IS BLANK
• Check circuit breaker and reset if necessary .
• Make sure power switch at heating & cooling
system is on .
• Make sure furnace door is closed securely .
• If thermostat is battery powered, make sure fresh AA
alkaline batteries are correctly installed .
TEMPERATURE SETTINGS DO NOT CHANGE
Make sure heating and cooling temperatures are set to
acceptable ranges:
• Heat: 45° to 90°F (7° to 32°C) .
• Cool: 50° to 99°F (10° to 37°C) .
HEATING SYSTEM DOES NOT RESPOND
("HEATING" APPEARS ON SCREEN)
• Check for 24 VAC at the equipment on the secondary
side of the transformer between power and
common . If voltage is not present, check the heating
equipment to find the cause of the problem .
• Check for 24 VAC between the heat terminal (W)
and the transformer common . If 24 VAC is present,
the thermostat is functional . Check the heating
equipment to find the cause of the problem .
• Check for loose or broken wires between the
thermostat and the heating equipment .
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