Aprilaire 8910 Thermostat User Manual


 
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TROUBLESHOOTING
TROUBLESHOOTINGQUICK REFERENCE TO CONTROLS & DISPLAY
DISPLAY IS BLANK
If Power LED not illuminated at the equipment control
module check the following.


system is on.

POWER/STATUS – On solid during normal operation. Flashes
when connection to the thermostat is lost and at power-up while
the thermostat connection is being established.
HEATING – On when heating outputs are active.
COOLING – On when cooling outputs are active.
FAN – On when fan output is active.
HUMIDIFIER – On when humidifier output is active.
DEHUMIDIFIER – On when dehumidifier output is active.
VENTILATION – On when ventilation output is active.
AIR CLEANING – On when air cleaner output is active.
HEATING SYSTEM DOES NOT RESPOND
(“HEATING” APPEARS ON SCREEN)

side of the transformer between power and

equipment to find the cause of the problem.


the Home Comfort Control is functional. Check the
heating equipment to find the cause of the problem.

Comfort Control and the heating equipment.
COOLING SYSTEM DOES NOT RESPOND
(“COOLING” APPEARS ON SCREEN)

side of the transformer between power and

equipment to find the cause of the problem


the Home Comfort Control is functional. Check the
cooling system to find the cause of the problem.

Comfort Control and the cooling equipment.
FAN DOES NOT TURN ON IN A CALL FOR HEAT

the fan control is properly set to match the type of
system.
HEAT PUMP ISSUES COOL AIR IN HEAT MODE,
OR WARM AIR IN COOL MODE

reversing valve is connected to the proper terminal.

HEAT/COOL BOTH ON AT SAME TIMEEQUIPMENT CONTROL MODULE LEDs

to match the installed heating/cooling equipment.

not shorted together.
HEATING EQUIPMENT IS RUNNING IN
COOL MODE

to match the installed heating/cooling equipment
(see page 11).
“HEATING” IS NOT DISPLAYED

(Control Setup) is set correctly.

the temperature level above the current room
temperature.
“COOLING” IS NOT DISPLAYED

(Control Setup) is set correctly.

the temperature level below the current room
temperature.
ERROR CODES


Error code Message Error Description
01

Open temperature sensor circuit
02 Shorted temperature sensor circuit
03  Error in permanent memory
05  Thermostat lost connection to equipment interface module
HOME COMFORT CONTROL
FEATURES

– Humidification automatic or manual control.
– Dehumidification.

air cleaning.
– Ventilation with temperature and humidity limits.


raises the room temperature 3°F to 5°F.

sensor.

constant backlight option available.


weekday/weekend schedules.

programming (batteries must be installed).




reminders.


schedule at any time.

the start of a program event.

your equipment.
