Friedrich AC Error Codes: Troubleshooting Guide

Friedrich is a family-owned business that comes with a rich history based in the city of San Antonio. From the San Antonio Zoo, Buckhorn Saloon, and Friedrich Wilderness Park, to Friedrich air conditioning the company has shown innovation, philanthropy, and ingenuity at its best. Ed Friedrich founded the business back in 1883 when the company designed furniture using the horns of the longhorn cattle. However, that is not where the story ended, the family was full of innovative thinkers who were constantly working on tending to the market’s needs.

Such innovative thinking and smart working is what brought the company its fame and glory to a point where the company was regarded as one of the best in the world. Offering solutions to consumers the company still focuses on offering products that match the time and needs of its consumers. Regardless of how high a company is ranked, or how well the appliance is reviewed, you are at the risk of an error. An error is not here to tell you it’s time to switch out your appliance, it’s a direct signal from the device – one that tells the owner something is wrong with the system that needs to be fixed. So rather than ignoring the error codes, your appliance is showing it’s time to note down the Friedrich Air conditioner error code and get to the bottom of the problem. To help you out we have listed down the most common error codes of Friedrich Air conditioners.

PTAC Codes

The Friedrich Smart Center continuously monitors the PTAC unit operation and will store service codes if certain conditions are witnessed. In some cases the unit may take action and shut the unit off until conditions are corrected.

PTAC – PD Series
Packaged Terminal Air Conditioners
Packaged Terminal Heat Pumps

Error CodesProblem
E1High pressure protection of system
E2Antifreezing protection
F0In defect of refrigerant
E4High discharge temperature protection of compressor
E5Overcurrent protection
E6Communication Malfunction
E8High temperature resistant protection
EEEEPROM malfunction
EULimit/decrease frequency due to high temperature of module
C5Malfunction protection of jumper cap
FoGathering refrigerant
F1Indoor ambient temperature sensor is open/short circuite
F2Indoor evaporator temperature sensor is open/short circuited
F3Outdoor ambient temperature sensor is open/short circuited
F4Outdoor condenser temperature sensor is open/short circuited
F5Outdoor discharge temperature sensor is open/short circuited
F6Limit/ decrease frequency due to overload
F8Decrease frequency due to overcurrent
F9Decrease frequency due to high air discharge
FHLimit/ decrease frequency due to antifreezing
PHVoltage for DC bus-bar is too high
PLVoltage of DC bus-bar is too low
P0Compressor Min frequence in test stat
P1Compressor rated frequence in test state
P2Compressor maximum frequence in test state
P3Compressor intermediate frequence in test stat
P5Overcurrent protection of phase current for compressor
PUCharging malfunction of capacitor
P7Malfunction of module temperature sensor circuit
P8Module high temperature protection
H0Decrease frequency due to high temperature resistant during heating operation
H1Defrosting
H2Static dedusting protection
H3Overload protection for compressor
H4System is abnormal
H5IPM protection
H6Internal motor (fan motor) do not operate
H7Desynchronizing of compressor
HCPFC protection
L3Outdoor DC fan motor malfunction
L9Power protection
LPIndoor unit and outdoor unit doesn't match
LCFailure startup
U1Malfunction of phase current detection circuit for compressor
U3Malfunction of voltage dropping for DC bus-bar
U5Malfunction of complete units current detection
U7The four-way valve is abnormal
U9Zerocrossing malfunction of outdoor unit
A2There is an issue with the power supply to the heater.

Window/Room AC Codes

Friedrich Window Room Air Conditioner Error Codes
Friedrich Window Room Air Conditioner Error Codes
Fault CodesSolution
CH01Indoor Air Sensor Error. Indoor air sensor open or short.
CH09EEPROM CheckSum Error. EEPROM reading date error.
CH34High Pressure Error. As high pressure,comp off over 10 times in 1 hour.

Portable Codes

Friedrich Portable Error Codes
Friedrich Portable AC Error Codes and Troubleshooting
Error CodesCause
E1Electrical short on both temperature sensor and PCB.
E2Electrical short of temperature sensor copper tube and PCB wiring.
E4Indicates water tank full or poor contact of signal plug. User needs to pull out the rubber stopper which is located at the bottom of the unit, to drain the water away. Check that the plug has been wired correctly.

Portable AC Troubleshooting

Friedrich Portable AC Troubleshooting
Friedrich Portable AC Troubleshooting
ProblemPossible Cause
The airconditioner doesn't workThere is a power failure, Wait for the power return.
The plug is not connected. Connect the plug.
The timer is unable to work. Provide repairment.
The main switch has not been pressed. Press the main switch.
The airconditioner works for short period onlyThe set temperature is too close to the room's temperature. Decrease the setting temperature.
There is something blocking the suction vent on the back of condenser. Remove any obstacles.
The fan on the condenser is blocked. Provide repairment.
The airconditioner switches are off constantlyMalfunction. Turn off the appliance remove the plug and contact the service center.
The appliance is very noisy and vibrates violentlyThe compressor blocking device has been loosen or the copper pipe is getting in touch with the body of the set. Provide repairment.
When LED of unit shows E1There might be a broken or short circuit on ambient temperature sensor. Please check if it is sensor's problem. If not, contact manufacturer for replacing the PCB.
When LED of unit shows E2There might be a broken or short circuit on brass temperature sensor (only applicable for cooI/heat unit). Please check if it is sensor's problem. If not, contact manufacturer for replacing the PCB.
Friedrich Portable AC Remote Control
Friedrich Portable AC Remote Control

Digital Control Diagnostics and Test Mode

Error CodePossible Cause
02An extreme low voltage condition exists <198V for 230V units and <239V for 265V units. Action Taken by Unit: Shut down unit. Display Error code and flash. Once voltage rises to normal level system power is restored.
03Return air thermistor sensor open or short circuit. Action Taken by Unit: Set return air sensor = 75°F. Alternate flash set point and error code. Leave unit running. Possible Cause: Defective sensor.
04Indoor coil thermistor sensor open Or short circuit. Action Taken by Unit: Set ID coil temp = 40°F. Alternate flash set point and error code. Leave unit running. Possible Cause: Defective sensor.
05Outdoor coil thermistor sensor open Or short circuit. Action Taken by Unit: SetOD coil temp = 20°F. Alternate flash set point and error code. Automatically change over to Electric heat Mode only. Leave unit running. Possible Cause: Defective sensor.
06If O.D. coil Temperature > 175 Deg F for 2 consecutive minutes. (Heat Pump models only). Action Taken by Unit: Alternate flash set point and error code. Shut unit down for 5 minutes, then try again 2 times, if fails the 3rd time, then shut down unit.
07I.D coil temperature <30 Deg F for 2 consecutive minutes. Action Taken by Unit: Alternate flash set point and error code. Continue fan operation while the compressor is locked out until the indoor coil thermistor reaches 45° F, and then energize the compressor. However, compressor must still wait a lockout time of 180 to 240 seconds.
08If unit cycles (Heat or Cool demand)> 9 times per hour. Action Taken by Unit: Alternate flash set point and error code. Keep unit running.
09If unit cycles (Heat or Cool demand)< 3 times per hour. Action Taken by Unit: Alternate flash set point and error code. Keep unit running.
10Room Freeze Protection triggered. Action Taken by Unit: Alternate flash set point and error code. Keep unit running. Possible Cause: Room temperature fell below 40°F.

Heat Pump Codes

Friedrich Thru-the-wall Air Conditioners and Heat Pumps
Friedrich Thru-the-wall Air Conditioners and Heat Pumps

Error Code Mode is used to display all error codes stored since reset. It is a sub-mode of Test Mode.

Error CodesProblem
E1SHORT CYCLE SITUATION: Defined as a compressor that starts and stops more frequently than it should (more than 6 times per hour).
E2KEYBOARD STUCK ERROR: If any key button is stuck or pressed for 20 seconds or more, the unit considers it stuck. If a key is stuck it will be ignored until released. If the “Mode” key is stuck, the unit’s function will default to Cool mode.
E3FROST PROBE OPEN: Normal operation is allowed. Replace probe.
E4FROST PROBE SHORT: Normal operation is allowed. Replace probe.
E5INDOOR PROBE OPEN: Control assumes indoor ambient temperature is 90 degrees F and unit will operate. Replace probe.
E6INDOOR PROBE SHORT: Control assumes ambient temperature is 90 degrees F and unit will operate. Replace probe.
E1SHORT CYCLE SITUATION: Defined as a compressor that starts and stops more frequently than it should (more than 6 times per hour).
E2KEYBOARD STUCK ERROR: If any key button is stuck or pressed for 20 seconds or more, the unit considers it stuck. If a key is stuck it will be ignored until released. If the “Mode” key is stuck, the unit’s function will default to Cool mode.
E3AMBIENT (INDOOR) AIR PROBE OPEN OR SHORT: Control will assume ambient temperature is 90 degrees F when in Cool mode and 60 degrees F when in Heat mode. Unit will operate (see note below).
E4EVAPORATOR TEMPERATURE PROBE OPEN OR SHORT: Normal operation is allowed. Replace probe.
E5CONDENSER TEMPERATURE PROBE OPEN OR SHORT: Normal operation is allowed. Replace probe.
E7MOTOR OPERATION
E9HEAT PUMP FAILURE

Unit must be in Test Mode to enter the Error Code function. Activating Error Code Mode: Press the TIMER On/Off” button (see figures 4 and 5). The LED for the TIMER On/ Off will flash 1 bps (beats per second) while Error Code Mode is active. Pressing the Temp/Hour button will display “00”. Consecutive presses will scroll through all error codes stored. Press the Temp/Hour button to see the reverse order of the error codes. When the end of the stored error codes is reached the temperature Set Point will appear. (Each error code is listed once).

figures 4 and 5
figures 4 and 5

Exiting Error Code Mode: press the Timer On/Off button.

Clearing Error Codes: Error codes are cleared from the memory by exiting from Error Code Mode.

Multi Zone AC Codes

Friedrich Multi Zone Air Conditioner
Friedrich Multi Zone Air Conditioner
Error CodesMeaning
00No Error
01Indoor Room themistor error
02Indoor in-piping sensor error
03Remote controller error
04Drain Pump error
05Communcation error between in and out
06Indoor Out-Piping sensor error
07Differnt mode operation
09EEPROM Check Sum Error
10Indoor BLDC Fan Lock
21DC Peak (IPM Fault) - Over Rated Current Off
22CT 2(Max CT) 2times - Input Over Current Off
23DC Link Low Volt. 2times - DC Link Volt is below 140Vdc Off
24L_P/H_P Switch - Low/High Press Switch Open Off
25Low Voltage/Over Voltage - Abnormal AC Volt Input Off
26DC Compressor Position Error - Compressor Starting Fall Error Off
27PSC/PFC Fault Error - Inverter PCB input current is over100A(peak) for 2us Off
28DC Link High Volt - Off Off
29COMP Over Current - Over Inverter Compressor Current Off
32D-Pipe High (INV) - Off Off
40CT Sensor (Open / Short) - CT Circuit Malfunction Off
41INV. D-Pipe Th Error - Open/Short Off
44Outdoor Air Th Error - Open/Short Off
45Cond. Pipe Th Error - Open/Short Off
46Suction Pipe Error - Open/Short Off
51Capacity Over 5times - Over combination Off
52Signal Error(DSP Board <-> Main Board) - Communication Poorly Off
53Signal Error (Indoor <-> Outdoor) - Communication Poorly Off
60EEPROM Check Sum Error - Check Sum Mismatching Off
61Cond. Pipe Th High - Cond. Temp. High Off
62Heatsink Th High -Heatsink Temp. High Off
65Heatsink Th Error - Open/Short Off
67Outdoor BLDC Fan Lock - Outdoor Fan is not operating Off
73PFC Fault Error(S/W) - Over Current of Outdoor Unit PFC

Alarm Status

Error CodesProblem
1Maintenance ICON: Flash. Front Panel Button Stuck For More Than 20 Seconds Continue to monitor for "OPEN" (Unstuck) switch. Do not process switch input. ENSURE FRONT COVER DOES NOT DEPRESS BUTTONS
2Maintenance ICON: Flash. Input Voltage Out of Specification (103 - 127 / 187 - 253) Stop.Open all relays until voltage is back within specs. Resume operation.
3Maintenance ICON: Flash. Indoor Temperature Sensor is Open or Shorted Set temp to 75°F in COOLING or 68°F in HEATING. Unit continues to operate.
4Maintenance ICON: Flash. Indoor Coil Temperature Sensor is Open or Shorted Control Board sets temp to 40°F. Override sensor. Unit Continues to operate.
5Maintenance ICON: Flash. Outdoor Coil Temperature Sensor is Open or Shorted Sets temp to 20°F. Override sensor. Continue operation. Use Elec Heat if available for HEATING. If not available use HEAT PUMP if outdoor temp allows.
6Maintenance ICON: Flash. Outdoor Coil > (grater than) 175 F. Shut down for 5 min. Resume operation for 3 min. Continues to monitor. If test fails 3 times, the severity is increased and the unit operation is locked out.
7Maintenance ICON: Flash. Indoor Coil < (less than) 30 F for 2 consecutive minutes Turn compressor off. Run High Fan speed. When coil temp reachs 45°F resume operation after lockout time.
8Maintenance ICON: Log Only. Unit Cycles > (grater than) 9 Times per hour. Continue operation. Continue to monitor. Take no action. Log Only.
9Maintenance ICON: Log Only. Unit Cycles < (less than) 3 Times per Hour. Continue operation. Continue to monitor. Take no action. Log Only.
10Maintenance ICON: Log Only. Room Freeze Protection Only used if Electric Heat is available. Run High Speed and Electric heat until room temp reaches 46°F. Display "FRZ" during operation. Logged Only.
11Maintenance ICON: On. WallStat Problem or Connection Issue Severity 4 error is. Unit operates based on standard input mapping. Severity 2 error opens all relays. Unit will not operate.
12Maintenance ICON: Flash. Discharge Air > (greater than) 185 F Shutdown heat pump and electric heater. Run high fan speed until temp is 100°F. Resume operation. Third occurance in 1 hour locks unit out.
13Maintenance ICON: Flash. Prerssure Limit Switch Open If unit is cooling or heat pump on,shut down compressor. Run high fan until switch closes. Resume operation. Third occurance in 1 hour locks unit out.
14Maintenance ICON: Flash. Discharge Air Temperature Sensor is Open or Shorted Override Sensor. Set temp to 75°F. Continue to monitor. Set error code 14 ON.
15Maintenance ICON: Solid On. Heat Pump Error. If indoor coil temp < (Lesser than) ambient temp for 3 minutes. Unit uses electric heat to satisfy heating demand.
16Maintenance ICON: Flash. Temperature Beyond Operating Limits. Ambient temp < (less than) 0°F and ambient temp > (greater than) 130°F. Set error code 16 ON. When cleared return unit to normal.
17Maintenance ICON: Flash. Equipment Doesn't Meet Minimum Configuration. Must have compressor enabled and at least 2 fan speeds
18Maintenance ICON: Flash. Special Test 1 Severity Level 1. Unit shuts down. Inputs via front panel or t-stat are ignored. Qualified Technical Service required URGENT.
19Maintenance ICON: Flash. Special Test 2 Severity Level 2. Unit operates. Qualified Technical Service required.
20Maintenance ICON: Solid On. Special Test 3 Severity Level 3 Error is Logged Only. Unit operates. Severity 3 keeps unit running. Attention is needed.
21Maintenance ICON: OFF, Log Only. Special Test 4 Severity Level 4 Error is Logged Only. Unit operates. Severity 4 keeps unit running.
22Maintenance ICON: OFF, Log Only. Outdoor Coil Temperature < 30 F for 2 consecutive Minutes. Unit will use electric heat to satisfy heating demands until temp > 45°F. Unit must be a Heat Pump.
23Maintenance ICON: OFF, Log Only. Frost Protection (for Heat Pump Only Unit- YS10M10) Unit will run active defrost for a minimum of 6 minutes when Heat Pump run time is greater than 60 minutes and outdoor coil temp is 26 F or less.
24Maintenance ICON: Flash, Outdoor Air Temperature Sensor is Open or Shorted. Continue with normal operation. Continue to monitor sensor.

Wiring Diagram

Wallmaster Wiring Diagram Electronic Control Cool Only Models

Wallmaster Wiring Diagram Electronic Control Cool Only Models
Wallmaster Wiring Diagram Electronic Control Cool Only Models

Manuals Pdf

Heat Pump Manual

PTAC Installation And Operation Manual

Portable AC Manual

Quietmaster Manual

Pde12k3sg Manual

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