Troubleshooting; Error Codes; Thermostat Features - Aprilaire 8620 Safety & Installation Instructions

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: 40° to 90°F (4° to 32°C) .
• Cool: 50° to 99°F (10° to 37°C) .
HEATING SYSTEM DOES NOT RESPOND
("HEATING" APPEARS ON SCREEN)
• Check for 24VAC 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 24VAC between the heat terminal (W)
and the transformer common . If 24VAC 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 .
COOLING SYSTEM DOES NOT RESPOND
("COOLING" APPEARS ON SCREEN)
• Check for 24VAC 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 24VAC between the cooling terminal (Y)
and the transformer common . If 24VAC 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 05 (Fan Control), to make sure
the fan control is properly set to match the type of
system (see page 8) .
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HEAT PUMP ISSUES COOL AIR IN HEAT MODE,
OR WARM AIR IN COOL MODE
• Check System Setting 31 (O/B Operation) to make
sure the reversing valve operation matches the heat
pump .
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 8) .
• 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 8) .
"HEATING" IS NOT DISPLAYED
• Check Installer System Setting number 01
(Control Setup) is set correctly .
• Change the System Mode to Heat, and set
the temperature level above the current room
temperature .
"COOLING" IS NOT DISPLAYED
• Check Installer System Setting number 01
(Control Setup) is set correctly .
• Change the System Mode to Cool, and set
the temperature level below the current room
temperature .
HUMIDIFIER DOES NOT OPERATE IN
AUTO MODE
• Check Installer System Setting number 11 (Outdoor
Sensor) is set to yes .
• Verify that the outdoor sensor is functioning
correctly . If the sensor is functioning correctly the
outdoor temperature will display in the outdoor
temperature location (see Home Screen on page 17
for the location) .

ERROR CODES

If the thermostat enters an error mode, all outputs are turned off . The thermostat attempts to recover every 10 minutes .
If the error does not clear, use the reset button . This will return all settings back to factory default .
Error code Message
01
"SENSOR ERROR"
02
04 "EEPROM ERROR"

THERMOSTAT FEATURES

• Indoor air quality control .
– Humidification automatic or manual control .
– Dehumidification .
– Event-Based air cleaning .
™
– Ventilation with temperature and humidity limits .
• Temperature control .
• Heat Blast raises the room temperature 3°F to 5°F .
™
• Large touch screen with adjustable backlight –
constant backlight option available .
• Message center provides feedback and instructions .
• 7 day programmability or separately programmable
weekday/weekend schedules .
• Thermostat can be removed from the wall for easy
programming (batteries must be installed) .
Error Description
Open temperature sensor circuit
Shorted temperature sensor circuit
Error in permanent memory
• Dual power option (24VAC or battery) .
• Front battery door access for fast, easy replacement .
• Displays room temperature, room humidity,
temperature setting, and outdoor temperature .
• Air filter, humidifier, dehumidifier, and HVAC service
reminders .
• Programmable fan control with fan circulation mode .
• Easy to use temperature control can override program
schedule at any time .
• Progressive recovery ensures proper temperature at
the start of a program event .
• Built in compressor protection prevents damage to
your equipment .
• System test mode .
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