Troubleshooting; Error Codes; Home Comfort Control Features - Aprilaire Home Comfort Control 8910 Safety & Installation Instructions

QuICK RefeRenCe To ConTRols & DIsPlay
eQuIPMenT ConTRol MoDule leDs
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 .

TRoublesHooTIng

DIsPlay Is blanK
If Power LED not illuminated at the equipment control
module check the following .
• C heck circuit breaker and reset if necessary.
• M ake sure power switch at heating & cooling
system is on .
• M ake sure furnace door is closed securely.
HeaTIng sysTeM Does noT ResPonD
("HeaTIng" aPPeaRs on sCReen)
• C heck 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 .
• C heck for 24VAC between the heat terminal (W)
and the transformer common. If 24VAC is present,
the Home Comfort Control is functional . Check the
heating equipment to find the cause of the problem .
• C heck for loose or broken wires between the Home
Comfort Control and the heating equipment .
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CoolIng sysTeM Does noT ResPonD
("CoolIng" aPPeaRs on sCReen)
• C heck 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
• C heck for 24VAC between the cooling terminal (y)
and the transformer common. If 24VAC is present,
the Home Comfort Control is functional . Check the
cooling system to find the cause of the problem .
• C heck for loose or broken wires between the Home
Comfort Control and the cooling equipment .
fan Does noT TuRn on In a Call foR HeaT
• C heck System Setting 09 (Fan Control), to make sure
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
• C heck wiring at the terminal block to confirm the
reversing valve is connected to the proper terminal .
O is active in cooling and B is active in heating.
TRoublesHooTIng
HeaT/Cool boTH on aT saMe TIMe
• C heck SW1 (Equipment Type), to make sure it is set
to match the installed heating/cooling equipment .
• C heck to make sure heating and cooling wires are
not shorted together .
HeaTIng eQuIPMenT Is RunnIng In
Cool MoDe
• C heck SW1 (Equipment Type), to make sure it is set
to match the installed heating/cooling equipment
(see page 11) .

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
03 "EEPROM ERROR"
05 "LOST SySTEM CONNECTION"
HoMe CoMfoRT ConTRol feaTuRes
™
• I ndoor air quality control.
– Humidification automatic or manual control .
– Dehumidification .
– Event-Based ™ air cleaning .
– Ventilation with temperature and humidity limits .
• T emperature control.
• H eat Blast raises the room temperature 3°F to 5°F .
™
• S upport for optional wireless outdoor temperature
sensor .
• L arge touch screen with adjustable backlight –
constant backlight option available .
• M essage center provides feedback and instructions.
• 7 day programmability or separately programmable
weekday/weekend schedules .
• T hermostat can be removed from the wall for easy
programming (batteries must be installed) .
"HeaTIng" Is noT DIsPlayeD
• C heck Installer System Setting number 05
(Control Setup) is set correctly .
• C hange the System Mode to Heat, and set
the temperature level above the current room
temperature .
"CoolIng" Is noT DIsPlayeD
• C heck Installer System Setting number 05
(Control Setup) is set correctly .
• C hange the System Mode to Cool, and set
the temperature level below the current room
temperature .
error Description
Open temperature sensor circuit
Shorted temperature sensor circuit
Error in permanent memory
Thermostat lost connection to equipment interface module
• F ront battery door access for fast, easy replacement.
• D isplays room temperature, room humidity,
temperature setting, and optional outdoor temperature.
• A ir filter, humidifier, dehumidifier, and HVAC service
reminders .
• P rogrammable fan control with fan circulation mode.
• E asy to use temperature control can override program
schedule at any time .
• P rogressive recovery ensures proper temperature at
the start of a program event .
• B uilt in compressor protection prevents damage to
your equipment .
• S ystem test mode.
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