Carrier Energy Recovery Ventilators
60 fault codes documented
Fault Code 1 — OVERCURRENT
The output current is excessive. This means the motor is drawing more current than it should.
Fault Code 2 — DC OVERVOLT
The intermediate circuit DC voltage is too high. This can happen during deceleration or due to power supply issues.
2 Red Flashes — Limit Switch Fault
The system has detected a limit switch fault. The gas valve and igniter will be off, but the indoor fan and inducer will remain on.
Fault Code 3 — DEV OVERTEMP
The drive's heat sink is overheated, reaching or exceeding 115°C (239°F).
3 Red Flashes — Flame Sense Fault
The control sensed a flame when the gas valve should be closed. The indoor fan and inducer will be on.
Fault Code 4 — SHORT CIRC
A short circuit fault has been detected. This is indicated by fault current.
4 Red Flashes — Four Consecutive Limit Switch Faults
This indicates four consecutive limit switch faults occurred within a single heating cycle. No gas heating will occur.
Fault Code 5 — OVERLOAD
The drive is experiencing an inverter overload condition, meaning the output current exceeds its ratings.
5 Red Flashes — Ignition Fault
The unit failed to ignite successfully after 15 minutes of attempts. No gas heating will occur.
Fault Code 6 — DC OVERVOLT
The intermediate circuit DC voltage is insufficient. This can occur if the input power is unstable.
6 Red Flashes — Induced Draft Motor Fault
This fault relates to the induced draft motor. If the heat is off, there will be no gas heating. If heat is on, the gas valve will be off and the inducer will be on.
Fault Code 7 — Al1 LOSS
Analog input 1 has lost its signal. The value is less than the set limit.
7 Red Flashes — Rollout Switch Lockout
The rollout switch has opened, causing a lockout. The gas valve and igniter are off, but the indoor fan and inducer are on.
Fault Code 8 — Al2 LOSS
Analog input 2 has lost its signal, falling below the set limit.
8 Red Flashes — Internal Control Lockout
The IGC has detected an internal hardware or software error. No gas heating will occur.
Fault Code 9 — MOT OVERTEMP
The drive estimates that the motor is too hot. This can be due to overload or incorrect parameter settings.
9 Red Flashes — Temporary Software Lockout
Electrical interference is disrupting the IGC software, causing a temporary lockout. No gas heating will occur.
Fault Code 10 — PANEL LOSS
Communication has been lost with the control panel. This fault occurs if the drive is in local control mode or if remote control mode is set to accept commands from the panel.
11 Fault Code — ID RUN FAIL
The motor identification run could not be completed successfully.
12 Fault Code — MOTOR STALL
The motor or process is stalled, operating in the stall region. This is usually due to excessive load or insufficient motor power.
14 Fault Code — EXT FAULT 1
The digital input configured for the first external fault is active.
15 Fault Code — EXT FAULT 2
The digital input configured for the second external fault is active.
16 Fault Code — EARTH FAULT
The load on the input power system is out of balance, indicating a potential earth fault.
17 Fault Code — UNDERLOAD
The motor load is lower than expected, suggesting a possible issue with the connected load.
18 Fault Code — THERM FAIL
An internal fault has occurred. The thermistor measuring the drive's internal temperature is open or shorted.
19 Fault Code — OPEX LINK
An internal fault has been detected related to communication between the OMIO and OINT boards.
A154 — Serial EEPROM Hardware Failure
A hardware failure has occurred with the serial EEPROM, resulting in a unit shutdown.
A156 — Critical Serial EEPROM Storage Fail Error
A critical failure in the serial EEPROM storage has occurred, causing a unit shutdown.
A157 — A/D Hardware Failure
The Analog-to-Digital (A/D) hardware has failed, resulting in a unit shutdown.
A163 — Circuit A Down Due to Failure Lockout
Circuit A is locked out due to accumulating three strikes or another alarm condition.
A164 — Circuit B Down Due to Failure Lockout
Circuit B is locked out. This can occur after accumulating three fault strikes or being triggered by another alarm.
A200 — Linkage Timeout Error — Comm Failure
A communication failure has occurred, indicated by a linkage timeout error. The system will fall back to local SPT operation.
A404 — Fire Shutdown — Smoke Detected
The unit has shut down because smoke has been detected by a smoke detector.
Alarm (Green LED Flashing) — Advisory Diagnostic
For less severe errors (alarms), the drive flashes its green LED and displays an advisory message on the control panel. The drive is reporting an unusual condition.
D12 Green LED lit — ERV Wheel Status Alarm
This light indicates that the ERV wheel is not rotating when it should be. The system will signal an alarm.
D16 Green LED lit — ERV Dirty Filter Alarm
This light means the system has detected a dirty filter. This can affect the unit's performance.
D18 Green LED lit — ERV Blower Status Alarm
This indicates a blower or fan failure. The unit may not be able to move air effectively.
EXCB Motor Failure Alarm — Intake or Exhaust Motor Problem
This alarm is triggered if the outside air or exhaust motor detects a problem, such as phase loss or thermal overload. The system will close its alarm contact, visible as 24vac at EXCB J8-3.
OAU LOW CFM — Not enough outside air is being drawn in
This alarm means the ERV is not achieving the desired amount of outside air. The actual outside air CFM is less than 10% of the commanded amount.
OAU Motor Failure Alarm — Intake or Exhaust Motor Problem
This alarm indicates a problem with one of the ERV's outside or exhaust motors. The system will signal this through the OAU Motor Failure Alarm point.
Red LED flashing — Fault condition requiring reset
A flashing red LED indicates a fault condition that requires a specific reset procedure.
T111 — Circuit B Loss of Charge Lockout
This indicates a loss of charge in Circuit B, likely due to low refrigerant or a faulty pressure transducer.
T126 — Circuit A High Discharge Pressure Shutdown
Circuit A has shut down due to high discharge pressure. This can be caused by several factors related to system overcharge or restrictions.
T127 — Circuit B High Discharge Pressure Shutdown
Circuit B has shut down due to high discharge pressure. This is often related to system overcharge or airflow restrictions.
T133 — Circuit A Low Refrigerant Pressure
This indicates low refrigerant pressure in Circuit A. Several factors can contribute to this condition.
T134 — Circuit B Low Refrigerant Pressure
Circuit B is experiencing low refrigerant pressure. This can be caused by issues with refrigerant charge, airflow, or components.
T143 — Circuit A Failure To Pressurize
Circuit A is failing to pressurize. This usually points to issues with compressor operation or wiring causing reverse rotation.
T144 — Circuit B Failure To Pressurize
Circuit B is experiencing a failure to pressurize, often due to wiring issues affecting compressor rotation or a faulty compressor.
T153 — Real Time Clock Hardware Failure
The unit's real time clock hardware has failed, meaning it cannot operate on its time and date schedule.
T155 — Serial EEPROM Storage Failure Error
This error indicates a failure in the serial EEPROM's storage function, leading to unit operation errors.
T173 — Loss of communication with the Energy Management Module
Communication has been lost with the Energy Management Module. The unit will not take any action related to it.
T175 — Loss of communication with VFD
Communication has been lost with the Variable Frequency Drive (VFD), causing the unit to shut down.
T179 — Loss of communication with the Economizer Control Board
Communication has been lost with the Economizer Control Board (ECB), resulting in no economizer operation.
T180 — Loss of communication with the Economizer Actuator
There is no communication with the economizer actuator, meaning it will not operate.
T181 — Loss of communication with Outside Air Unit
Communication with the Outside Air Unit (OAU) has failed, prompting a reset of OAU data.
T408 — Dirty Air Filter
An alert has been generated because the air filter is dirty.
T409 — Fan Status Switch Fault
The fan status switch is indicating an incorrect state. This can lead to a unit shutdown if configured.
T410 — R-W1 Jumper Not Installed in Space Temp Mode
The R-W1 jumper is not installed, preventing the unit from running heat in Space Temperature Mode.
T411 — Thermostat Y2 Input Activated without Y1 Activated
The thermostat's Y2 input is activated while Y1 is not, causing the unit to run as if both Y1 and Y2 were on.
T418 OAU LOW CFM — Not enough outside air is being drawn in
This alarm indicates that the ERV cannot bring in the desired amount of outside air. The actual outside air CFM is less than 10% of the commanded amount after 10 minutes.