Aprilaire 8476 Thermostat User Manual


 
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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.
TROUBLESHOOTING
COOLING SYSTEM DOES NOT RESPOND
(“COOLING” 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 cooling
equipment to find the cause of the problem.
• Check for 24 VAC between the cooling terminal (Y)
and the transformer common. If 24 VAC is present,
the thermostat is functional. Check the cooling
system to find the cause of the problem.
• Check for loose or broken wires between the
thermostat and the cooling equipment.
FAN DOES NOT TURN ON IN A CALL FOR HEAT
• Check System Setting #02 (Fan Control), to make
sure the fan control is properly set to match the type
of system (see page 11).
HEAT PUMP ISSUES COOL AIR IN HEAT MODE,
OR WARM AIR IN COOL MODE
• Check System Setting #12 (Reversing Valve), to make
sure it is properly configured for your system (see
page 12).
HEAT/COOL BOTH ON AT SAME TIME
• Check SW1 (Equipment Type), to make sure it is set
to match the installed heating/cooling equipment
(see page 11).
• Check to make sure heating and cooling wires are
not shorted together.
HEATING EQUIPMENT IS RUNNING IN
COOL MODE
• Check SW1 (Equipment Type), to make sure it is set
to match the installed heating/cooling equipment
(see page 11).
“HEATING” IS NOT DISPLAYED
• Change the System Mode to Heat, and set
the temperature level above the current room
temperature.
“COOLING” IS NOT DISPLAYED
• Change the System Mode to Cool, and set
the temperature level below the current room
temperature.