Specifications
IM 934-5 Page 43 of 48
Solid State Digital Controls – Local User Interface Display Codes
Fault code Description Cause for the fault
AU Auto Damper Control setup indicator damper is in "automatic" mode.
Au Auto HP/E Control setup indicator heat pump electric is in automatic changeover mode (HP/E).
bo
Brown Out or Brown Out - Control monitors input voltage to prevent relay chattering. When voltage drops below
Low Voltage 17 VAC, outputs are disabled until voltage input increases to 20 VAC or greater.
bY HP/E Bypass Control setup indicator, electric heat is bypassed when OCS > 40˚.
CE LUI Communication Communication Error, connection between LUI and control board.
CL Damper Closed Control setup indicator damper is in "closed" mode.
CF Coil Freeze Protection Indoor coil is ≤ 32˚ for at least 5 minutes. Compressor and outdoor fan stop and indoor fan continues
to run for active defrost. Protection feature and the displayed code are dismissed when indoor coil
temperature rised above 49°F.
Hi Temperature Limiting Hi Room Room Temperature Display Indication ONLY - Indoor air temperature is 5° above Maximum
set point. Displayed code is dismissed when IAS temperature is < 5° from Max set point as adjusted in
the Set Up Mode.
LA Low Ambient Lockout Unit is in cooling mode and outdoor air < 25˚. Compressor will cut out.
Slave Unit Set to be When slave unit jumper for Control Select is positioned over SEC, slave unit is set to be controlled by
Controlled by a Master Unit a Master control unit.
LC Control Lockout – Displays for 5 seconds when any button is pushed when in the "lockout mode".
Lockout Mode To initiate, hold MODE button for 10 seconds.
Lo Temperature Limiting Low Room Room Temperature Display Indication ONLY - Indoor air temperature is < 5° below
minimum set point. Displayed code is dismissed when IAS temperature is > 5° from Minimum set
point as adjusted In the Set Up Mode.
nL Control Lockout – Displays for 5 seconds to conrm normal mode of operation when control lock out turned off. Initiate
Normal Control by holding MODE button for 10 sec.
rF Room Freeze Protection Room temperature < 41˚. Damper closes (Premium board) and unit goes into heat mode.
Sh Jumper Status Missing Shunt or not properly installed.
E1 Indoor Air Sensor Indoor Air Thermister Failure. Sensor missing or Short.
E2 Indoor Coil Sensor Indoor Coil Thermister Failure. Sensor missing or Short.
E3 Outdoor Coil Sensor Outdoor Coil Thermister Failure. Sensor missing or Short.
E4 Outdoor Air Sensor Outdoor Air Thermister Failure. Sensor missing or Short.
E5 Heat Fan Lock Out Heat Fan Lock Out Sensor Failure, missing, short on control board or heating medium >250°F.
Sensor Check for installation/connection of HFLO sensor. Should be on coil return line.