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Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Possibly the electrical system that provides power to your furnace has shorted or blown the power switch. Reset your Keeprite furnace’s circuit breaker. If it is blown, you’ll have to replace it.
Igniter The furnace’s igniter could be cracked or faulty. Check if the part has cracks. If it does, then replace the igniter. If it doesn’t, use a multimeter to test for continuity.
Cycling irregularly? Thermostat The thermostat of your furnace might be adjusting incorrectly. If your thermostat has an adjustable calibration scale, adjust the heat anticipator. If this does not address the problem or you don’t have a scale, you may have to replace the thermostat.
Not blowing hot air? Blower Motor The blower motor may have burnt out. If this doesn’t seem likely, then the connecting belt may have broken. Test to see if power is reaching the motor. If it does, but nothing is running, the motor has likely failed and needs replacing. If the motor runs but air doesn’t move, the connecting belt has probably broken. You’ll have to replace the belt.
Blowing too much air? Control Board If the relay that regulates the blower motor on the control board has failed, it will continually send voltage to the motor. Replace the control board.
Thermostat The contact that controls the blower motor on your thermostat may be stuck closed. The result is that the blower motor will run continuously. Use a multimeter to check for continuity. If the issue is the thermostat, replace it.
Starting and then stopping shortly after? Flame Sensor Your furnace’s flame sensor monitors the burner, detecting if a flame is present. It's either defective, or there is debris, and won't be able to detect a flame. If dirty, carefully clean the sensor using a fine abrasive pad. If not, replace the flame sensor.
Error Codes What this means How to fix it
LED flashes like a heartbeat Control has 24 VAC power n/a
Two LED flashes Unit’s pressure switch didn’t open Check for an obstruction in the pressure tubing
Three LED flashes Unit’s pressure switch didn’t close or reopened Check for: excessive wind; proper vent size; defective inducer motor; defective pressure switch; inadequate combustion air supply; disconnected or obstructed pressure tubing; or restricted vent
Four LED flashes Limit circuit fault: either a limit or flame rollout is open Check for: restricted vent; proper vent sizing; loose blower wheel; excessive wind; dirty air filter; or defective blower
Five LED flashes An abnormal flame proving signal, the flame is likely proved while the gas valve is de-energized Check for a leaky gas valve or a gas valve that is stuck open
Six LED flashes Failure to ignite or the flame sensor was lost while running Check for: an ungrounded flame sensor; defective hot surface ignitor; low inlet gas pressure; oxide buildup; manual valve shut off; control ground continuity; inadequate flame carryover; or rough ignition
Seven LED flashes Limit circuit lockout A lockout will occur if the limit or flame rollout is open for longer than 3 minutes. Control will auto-reset after 3 hours
Eight LED flashes Gas heating lockout, control won’t auto-reset Check for a miswired gas valve or a defective control valve
Ten LED flashes Polarity is reversed Review instructions to correct polarity
1 + 2 The blower is on after power up Occurs if the unit is powered up during a call for heat or opens while the blower is on delay
6 + 1 Ignition lockout Control will auto-reset after 3 hours
LED is off Secondary voltage fuse is open Check whether the door switch isn’t closed or for a short circuit
LED is on Control circuitry lockout Will auto-reset after 1 hour
LED is solid Gas valve relay is stuck while open, flame sense circuit failure, or software-check error Reset power to clear the lockout and then replace control if status code repeats itself
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Fuse or Circuit Breaker The electrical system that provides power to your furnace has either shorted or blown the power switch. Reset your Keeprite furnace’s circuit breaker. If it is blown, you’ll have to replace it.
Igniter The furnace’s igniter is likely cracked or faulty. Check if the part has cracks and replace the igniter if it does. If it doesn’t, use a multimeter to test for continuity.
Cycling irregularly? Thermostat Your furnace’s thermostat may be adjusting incorrectly. If the thermostat has an adjustable calibration scale, you can adjust the heat anticipator. If this does not address the cycling or you don’t have a scale, you may have to replace the thermostat.
Not blowing hot air? Blower Motor The blower motor could have burnt out. If this isn’t the case, then the connecting belt could be broken. Check to see if power is going to the motor. If it is, but nothing is working, the motor is likely dead and needs to be replaced. If the motor runs but air doesn’t move, the connecting belt has probably broken and should be replaced.
Blowing too much air? Control Board If the relay that regulates the blower motor on the control board has stopped, it will continually send voltage to the motor. Replace the control board.
Thermostat The contact that controls the blower motor on your thermostat may be stuck shut. This results in the blower motor to run constantly. Use a multimeter to check for continuity. If the problem is the thermostat, replace it.
Starting and then stopping shortly after? Flame Sensor Your furnace’s flame sensor checks if a flame is present. If it's defective or there's debris, it won't be able to detect a flame. If dirty, carefully clean the sensor using a fine abrasive pad. If still not working, replace the flame sensor.
Error Codes What this means How to fix it
One LED flash that stays on continuously No signal from the thermostat. Turn off the unit’s power and check connections.
Single LED flash Furnace lockout due to an excessive number of ignition retries (3). Locate and correct gas interruption. Reset by lowering it for 20 seconds and then raise it back, furnace will reset itself after one hour.
Two LED flashes Draft inducer is not operating or the pressure switch circuit has closed. Replace the induced draft blower pressure switch, or repair the short.
Three LED flashes The pressure switch is open. Pressure switch may need to be replaced.
Four LED flashes Pressure issue. High limit cut-off due to faulty wiring or bad filters. Replace or clean the air filter; clean drain tubes of moisture or debris; may have an open limit switch that requires a jump, ensure not to run it with the main switch bypassed.
Five LED flashes The unit is sensing a flame without a call for heat. Might be the result of a slowly closing valve. Turn off the gas until the valve is fixed.
Seven LED flashes Faulty flame sensor. Flame sensor might be dirty or placed too far from flame. Clean if dirty, replace if defective.
Continuous LED flashing Polarity of volt power is reversed. Review wiring diagram to correct polarity.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Fuse or Circuit Breaker Either the power switch has blown, or the electrical system associated with your furnace has shorted. Either replace the blown switch or reset the circuit breaker associated with your furnace.
Igniter The furnace’s igniter is either cracked or defective. If the igniter is cracked, replace it. If it isn’t, test with a multimeter for continuity.
Cycling irregularly? Thermostat The furnace’s thermostat is adjusting incorrectly. Use your thermostat’s adjustable calibration scale to adjust the heat anticipator. If this doesn’t work or you don’t have a scale, replace the thermostat.
Not blowing hot air? Blower Motor Either the blower motor in your furnace has burned out, or the connecting belt has snapped. If the blower motor is receiving power but isn’t running, the motor has failed. If it does run, then the connecting belt has broken. Replace either the motor or belt depending on the outcome.
Blowing too much air? Control Board The relay responsible for regulating the amount of voltage that your blower motor receives has failed, resulting in the continual sending of voltage to the motor. Replace the control board.
Thermostat The contact that controls the blower motor on your thermostat could be stuck closed. Use a multimeter to check for continuity. If it appears that the thermostat is the issue, replace it.
Starting and then stopping shortly after? Flame Sensor If the flame sensor is either defective or dirty, it will not be able to detect whether or not a flame is present. If dirty, use a fine abrasive pad to clean the sensor. If faulty, replace the flame sensor.
Error Codes What this means What to check for
Steady LED flashing Normal operation n/a
Two LED flashes Pressure switch stuck closed Obstruction in pressure tubing
Three LED flashes Pressure switch stuck open or manual ON/OFF switch in off position Proper vent size; defective inducer motor; excessive wind; faulty pressure switch; disconnected or obstructed pressure tubing; inadequate combustion air supply; or restricted vent
Four LED flashes The limit switch is open Loose blower wheel; restricted vent; dirty air filter; defective blower; or excessive wind
Five LED flashes Flame has been sensed out of sequence The gas valve is either leaking or stuck open
Six +1 LED flashes Soft lockout: maximum trials for ignition has been reached n/a
Six +2 LED flashes Soft lockout: flame sense was lost while running, a cycling pressure switch, or blocked condensate n/a
Six +3 LED flashes Soft lockout: the pressure switch was opened during run n/a
Six +4 LED flashes Soft lockout: the limit switch was opened during run n/a
Seven LED flashes Soft lockout: the main limit was open for too long (1-hour delay) n/a
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Fuse or Circuit Breaker Your furnace’s electrical system has potentially shorted, or the power switch has blown. Reset the furnace-associated circuit breaker. If it has blown, you will have to replace it.
Igniter The furnace’s igniter might either be cracked or defective. Check the part for cracks, replace the igniter if it’s cracked.. If it isn’t, test with a multimeter for continuity.
Cycling irregularly? Thermostat Your unit’s thermostat might be adjusting incorrectly. Should the thermostat have an adjustable calibration scale, use this to adjust the heat anticipator. If this doesn’t work or you don’t have a scale, replace the thermostat.
Not blowing hot air? Blower Motor The blower motor might be burnt out. If this doesn’t seem to be the case, then the connecting belt may have snapped. First, see if power is reaching the motor. If it is but isn’t running, the motor has failed. If the motor runs but air doesn’t move, the connecting belt has probably broken. Replace the belt.
Blowing too much air? Control Board If the relay that regulates the blower motor on the control board has failed, it will continually send voltage to the motor. Replace the control board.
Thermostat The contact that controls the blower motor on your thermostat may be sticking. Use a multimeter to check for continuity. If it appears the thermostat is the issue, replace it.
Starting and then stopping shortly after? Flame Sensor Your furnace’s flame sensor detects if a flame is present. If it is either defective or dirty, it will not be able to detect a flame. If dirty, use a fine abrasive pad to clean the sensor. If faulty, replace the flame sensor.
Error Codes What this means How to fix it
LED flashing like a heartbeat Control has 24 VAC power n/a
Two LED flashes Unit’s pressure switch didn’t open Check for an obstruction in the pressure tubing
Three LED flashes Unit’s pressure switch didn’t close or reopened Check for: excessive wind; if it’s the proper vent size; defective inducer motor; defective pressure switch; inadequate combustion air supply; disconnected or obstructed pressure tubing; or restricted vent
Four LED flashes Limit circuit fault: either a limit or flame rollout is open Check for: restricted vent; loose blower wheel; excessive wind; dirty air filter; or defective blower
Five LED flashes An abnormal flame proving signal, the flame is likely proved while the gas valve is de-energized Check for a leaky gas valve or a gas valve that is stuck open
Six LED flashes Failure to ignite or the flame sensor was lost while running Check for: an ungrounded flame sensor; defective hot surface ignitor; control ground continuity; inadequate flame carryover; or rough ignition
Seven LED flashes Limit circuit lockout A lockout will occur if the limit or flame rollout is open for longer than 3 minutes. Control will auto-reset after 3 hours.
Eight LED flashes Gas heating lockout, control won’t auto-reset Check for a miswired gas valve or a defective control valve
Ten LED flashes Polarity is reversed Review instructions to correct polarity
1 + 2 Blower is on after power up Occurs if the unit is powered up during a call for heat or opens while the blower is on delay
6 + 1 Ignition lockout Control will auto-reset after 3 hours
LED is off Secondary voltage fuse is open Check whether the door switch isn’t closed or for a short circuit
LED is on Control circuitry lockout Will auto-reset after 1 hour
LED is solid Gas valve relay is stuck while open, flame sense circuit failure, or software-check error Reset power to clear the lockout and then replace control if status code repeats itself
American Standard Error Code What this means
Green light on, slow flashing, or fast flashing Unit is operating normally
Amber light on Unit requires refrigerant
Red 1 flash Communication error
Red 2, 3, and 4 flashes Defrost fault
Red 5 flashes Fault with the ambient temperature sensor
Red 6 flashes Fault with the coil temperature sensor
Red 7 flashes Low-pressure problem
Red 13 flashes Fault with the external temperature sensor
Red 17 flashes High-pressure problem
Is your air conditioner... The problem might be your... What's wrong? How you can fix it
Thermostat The batteries in your thermostat may be dead, or the thermostat may not be on the correct setting. Put new batteries in your thermostat and ensure that it is on the cool setting.
Circuit breaker The breaker switch may have flipped. Move the breaker switch back to the “on” position.
Not blowing cold air? Air filter If the filter is clogged with debris or dust, it won’t be able to do its job. Replace or clean your air filter so that air can flow freely.
Outside unit The air conditioner may not be able to have air flowing freely if there are dirt and debris around the unit. Make a two-foot space around your unit that is clear and free of leaves, greenery and any other blockage so that it can vent air properly.
Refrigerant If the refrigerant is leaking, your unit will not be efficient at cooling since there is less cooling fluid to run through your unit. Get a technician who can solve this problem.
Insulation Insulation is important to keep air from leaking out. Cracks, old windows and doors are all spots where cold air can escape. Windows are the main places where cool air escapes. Consider upgrading to insulated windows or use blackout curtains.
Dripping water? Condensate line The pipe that exits your air conditioner could be clogged. Blow compressed air through the pipe to dislodge the clog.
Drain line Water can overflow in the drain pan if the drain pipe is blocked. Check the drain line for any clogs and remove them.
Making odd sounds? Blower motor or belt Squealing sounds can come from the belt or the blower motor. Use lubricant on the parts to help them run better without squeaking.
Fan blades If the sound is repetitive like a card stuck in a bicycle spoke, there is a chance something is caught between the blades. Switch your unit off and check the fan blades to see if anything is trapped and remove it carefully.
Carrier Error Code What this means
Solid on, one flash, and two flashes Normal operation
Error Code 16 System communication failure
Error Codes 31 and 84 High-pressure problem
Error Codes 32 and 83 Low-pressure problem
Error Code 45 Fault with the control board
Error Codes 46, 47, 73, 74, 75, 76, 77, 78, 85, and 87 Voltage problems
Error Code 53 Fault with the outdoor temperature sensor
Error Code 55 Problem with the coil
Is your air conditioner... The problem might be your... What's wrong? How you can fix it
Thermostat The batteries in your thermostat may be dead, or the thermostat may not be on the correct setting. Put new batteries in your thermostat and ensure that it is on the cool setting.
Circuit breaker The breaker switch may have flipped. Move the breaker switch back to the “on” position.
Not blowing cold air? Air filter If the filter is clogged with debris or dust, it won’t be able to do its job. Replace or clean your air filter so that air can flow freely.
Outside unit The air conditioner may not be able to have air flowing freely if there are dirt and debris around the unit. Make a two-foot space around your unit that is clear and free of leaves, greenery and any other blockage so that it can vent air properly.
Refrigerant If the refrigerant is leaking, your unit will not be efficient at cooling since there is less cooling fluid to run through your unit. Get a technician who can solve this problem.
Insulation Insulation is important to keep air from leaking out. Cracks, old windows and doors are all spots where cold air can escape. Windows are the main places where cool air escapes. Consider upgrading to insulated windows or use blackout curtains.
Dripping water? Condensate line The pipe that exits your air conditioner could be clogged. Blow compressed air through the pipe to dislodge the clog.
Drain line Water can overflow in the drain pan if the drain pipe is blocked. Check the drain line for any clogs and remove them.
Making odd sounds? Blower motor or belt Squealing sounds can come from the belt or the blower motor. Use lubricant on the parts to help them run better without squeaking.
Fan blades If the sound is repetitive like a card stuck in a bicycle spoke, there is a chance something is caught between the blades. Switch your unit off and check the fan blades to see if anything is trapped and remove it carefully.
Is your air conditioner... The problem might be your... What's wrong? How you can fix it
Thermostat Dead batteries may be the cause, or the thermostat may be on the wrong setting. Replace the batteries and ensure that the thermostat is set to cool.
Circuit breaker The breaker switch may be turned off. Flip the switch back to the “on” position.
Not blowing cold air? Air filter The filter may not be effective if it is full of debris. Change or clean the air filter if you haven’t done so in a while.
Outside unit The air conditioner unit may be unable to vent hot air out properly if there is debris in the way. Clear out vegetation and leaves from near your unit, ensuring that you have at least 2 feet of clear space around your A/C.
Refrigerant Leaking refrigerant means that your unit is less efficient and won’t cool well. Call an HVAC technician to address this problem.
Insulation Inadequate insulation in the walls, windows or doors means that cool air can leak out while hot air gets trapped. Windows are common spots where air leaks out. Think about upgrading to insulating windows or use blackout curtains.
Dripping water? Condensate line The PVC pipe that exits your air conditioner may be blocked. Use compressed air to remove the blockage.
Drain line If the drain is clogged, water will end up overflowing from the drain pan and can get into internal parts and cause damage. Check the line and remove the clog before it causes more problems.
Making odd sounds? Blower motor or belt Squeaking sounds may mean that there’s an issue with the belt or blower motor. Applying lubricant can help the parts run better.
Fan blades If the sound is like a card stuck in a bicycle spoke, there may be something caught in the fan blades. Turn off power to your air conditioner and check if there is debris between the blades and carefully remove it.
Is your air conditioner... The problem might be your... What's wrong? How you can fix it
Thermostat Batteries may be dead, or the thermostat may be switched off. Change the batteries and check that the thermostat is set to cool.
Circuit breaker The breaker may have been switched off. Turn the switch to the “on” position.
Not blowing cold air? Air filter The filter may be clogged or full of debris. If you haven’t changed your air filter in a while or you’ve been running your A/C more than normal, it’s probably due for a change.
Outside unit The air conditioning unit outside your home may not be able to vent the hot air from your home properly. Check to make sure your unit has at least 2 feet of clear space. Remove vegetation and leaves from in, on and around your unit.
Refrigerant If the refrigerant is leaking, you won’t be getting cool air. Call an HVAC expert to fix the issue, since it requires trained expertise.
Insulation Old homes may have insulation gaps that let the cool air leak out. Windows are common culprits, consider replacing or using blackout curtains.
Dripping water? Condensate line The PVC pipe that leaves the A/C unit may be clogged. Use compressed air to clean it out and allow normal function.
Making odd sounds? Blower motor or belt Squealing may indicate that there is an issue with the belt or blower motor. Adding lubricant to the oil port can help the parts run smoothly.
Fan blades If the sound is more like a slapping noise, the problem may be with the blades of the fan. Something may be stuck in the blades. Turn off power to the unit to check if this is the cause and remove it.
Rheem Error Code What this means How to fix it
Error Code 0 Unit is on standby and operating normally. Normal operation.
Error Code C Unit is operating normally and in a cooling stage. Normal operation.
Error Code Flashing C Cooling was commanded during an active anti-short cycle. Wait until unit timer has expired or press the TEST button to defeat short cycle delay.
Error Code D1 No shared data. Replace memory card with correct system information.
Error Code D3 Airflow mismatch. Replace with properly sized air handler.
Error Code D4 Memory card in control board is invalid. Check if memory card is present and ensure it matches device.
Error Code D8 Old shared data system data is obsolete. If system will not operate, order new memory card to update system information.
Error Code T Unit is in test mode.
Error Code P There's no current going to the compressor. Check to see if the motor protector is open or line voltage is disconnected.
Error Code 1 The compressor is running continuously. Check to see if there is low refrigerant, air duct leakage, a dirty outdoor coil, or a dirty air filter.
Error Codes 02, 29, and flashing L29 High-pressure problem. Check if there is a dirty outdoor coil, outdoor fan is not running, liquid line restriction, or excessive refrigerant charge.
Error Code 03 Unit is short-cycling. Check thermostat wire connections (R. C. 1. & 2) and thermostat location in zone (too close to discharge grill).
Error Codes 05, 06, 07, L6, and L7 Problem with the compressor because of an open circuit. Check for damaged, miswired. or wrong run capacitor, broken wires, loose connectors, or miswired compressor, compressor windings for continuity, and open compressor internal protector.
Error Codes L4 The rotor is locked. Check if there is a bad run capacitor, low line voltage, excessive refrigerant in compressor, or seized bearings in compressor.
Error Code 09 Secondary voltage is low. Check if the control transformer is overloaded or for low line voltage.
Error Codes 21 and flashing L21 Low-pressure control is open. Check if unit has low refrigerant charge, indoor coil is frozen, dirty indoor coil or filter, indoor blower is not running, or expansion valve is not operating correctly.
Error Code 27 Low or no line voltage. Check incoming line voltage to the disconnect and unit and wiring connections.
Error Code 28 High line voltage fault. Check line voltage.
Error Code 30 On-board fuse is open. Check if low voltage wiring at R and C is damaged or miswired.
Error Code 80 Unit isn't meeting minimum airflow requirements. Replace with properly sized unit.
Error Code 83 Problem with the condenser coil temperature. Check sensor is installed correctly on control and replace the sensor.
Error Code 84 Problem with the outdoor ambient temperature fault. Check unit placement. If the outdoor unit is in a high temperature area, wait until the ambient temperature drops and check sensor reading. Check sensor is installed correctly on control. Replace the sensor.
Error Code 93 There's a problem with the internal control. Check control for proper system operation. Replace control.
Is your air conditioner... The problem might be your... What's wrong? How you can fix it
Thermostat Check the batteries. They may be dead, or the thermostat may be on the wrong setting. Replace the batteries in your thermostat and double check that it’s on the cool setting.
Circuit breaker The breaker switch may be turned off. Flip the switch back to the “on” position.
Not blowing cold air? Air filter The filter needs to be clean to do its job. If it’s clogged with dirt or dust, it won’t work. Replace or clean your filter to allow air to blow better.
Outside unit If the area around the unit has foliage, furniture or debris laying around it can stop air from flowing correctly. Clear a two-foot space around your air conditioner and keep it clean so that nothing blocks the airflow from your unit.
Refrigerant Leaking refrigerant will cause the unit to be less effective since there is not enough cooling fluid to work. A professional HVAC technician can fix this for you.
Insulation Without insulation, air can leak out from your home. Cracks, windows and doors are common areas where this happens. Consider upgrading your windows to ones that are more insulating or use blackout curtains to keep the sun and heat out.
Dripping water? Condensate line The pipe leaving your air conditioner may have debris inside it. Use compressed air to remove the clog.
Drain line If the drain pan is full, it can cause the drain line to be blocked and water to overflow. See if there are any blockages in the drain line and clear them. Empty your drain pan as well.
Making odd sounds? Blower motor or belt Squeaking sounds are typically from the belt or the blower motor. Lubricant can help the parts to run smoothly without squeaking.
Fan blades If the sound is like a card in a bicycle spoke, then it’s likely that something is stuck between the blades. Turn off the unit, open it carefully and check if there is something caught between the blades and extract it gently.
Rheem Error Code What this means
Error Code 10 There's a one-hour lockout in place.
Error Code 11 The ignition failed.
Error Code 12 Low flame detected.
Error Code 13 The flame was lost.
Error Code 14 There was an unexpected flame.
Error Code 20 There was a twinning fault.
Error Code 22 Problem with high limit.
Error Code 26 Reversal of line and neutral.
Error Code 33 Roll-out switch problem.
Error Codes 55 & 57 Pressure switch issue.
Error Codes 58 & 59 Water or condensation problem.
Error Code 61 Problem with the blower.
Error Code 93 Problem with the control.
York Error Code What this means
Error Codes E7 and F3, or 4 and 15 flashes Communication failure
Error Codes E1, E2, F21, F7, F6, and F25, or 10, 11, 12, and 13 flashes Sensor failure
Error Code E14 Indoor fan malfunction
Error Codes F19 or 6 flashes High voltage
Error Codes F8 or 9 flashes Outdoor fan malfunction
Error Codes F11 or 18 flashes Abnormal compressor function
Error Code F2 and F23, or 24 and 25 flashes Overcurrent problem
Goodman Error Code What this means
Red light on There's been a call for cold air, but the compressor isn't running
One yellow flash Compressor cycles are too long
Two yellow flashes High-pressure problem
Three yellow flashes Compressor cycles are too short
Four yellow flashes Rotor is locked, possibly because of a failed capacitor
Five, six, seven, or nine yellow flashes Problem with the circuits or voltage
Eight yellow flashes Compressor is always running
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Either the furnace’s circuit breaker has shorted or the fuse is blown. You’ll have to replace the blown switch or reset the furnace’s circuit breaker.
Igniter Your furnace’s igniter may be either cracked or defective. Should the igniter be cracked, you’ll have to replace it. Otherwise, test with a multimeter for continuity.
Cycling irregularly? Thermostat The thermostat is likely not adjusting correctly. If your thermostat has an adjustable calibration scale, use this to adjust the heat anticipator. If this doesn’t work or isn’t an option, replace the thermostat.
Not blowing hot air? Blower Motor Your unit’s blower motor has either burned out or the connecting belt has snapped. Troubleshoot to see if the blower motor is receiving power: if it isn’t running, the motor has failed, and you’ll have to replace it. If it does run, then the connecting belt has snapped, and you’ll have to replace the belt.
Blowing too much air? Control Board The relay that regulates the amount of voltage that is sent to your furnace’s blower motor on the control board has failed. You will have to replace the control board.
Thermostat Your thermostat’s contact that controls the blower motor’s functions might be stuck in a closed position. You’ll have to use a multimeter to check for continuity if this appears to be the issue then replace the thermostat.
Starting and then stopping shortly after? Flame Sensor Your furnace’s flame sensor detects whether or not a flame is present. Should the sensor be dirty or defective, it will not be able to read a flame’s presence. If the flame sensor is dirty, use an abrasive pad to wipe it clean. If it’s defective, replace the flame sensor.
Error Code What this means
LED is off No power being sent to the control, or a control hardware fault has been detected.
LED is on Normal operation.
Single LED flash The high limit switch is open.
Two LED flashes The pressure switch is open with the exhauster on.
Three LED flashes The pressure switch is closed with the exhausted off.
Four LED flashes Lockout due to too many failed ignition attempts.
Five LED flashes L1/Neutral Polarity problem.
Six LED flashes Too many limit trips within a single call for heat.
Seven LED flashes Pressure switch cycle lockout.
Eight LED flashes Lockout due to too many flame dropouts.
Nine LED flashes N/A
Ten LED flashes Flame has been sensed present while the gas is off.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse The electrical system that powers your furnace has likely shorted. Reset the circuit breaker that’s associated with your furnace.
Igniter The igniter might either be cracked or defective. Check to see if the igniter is cracked and needs replacing. Otherwise, test it with a multimeter for continuity.
Cycling irregularly? Thermostat The thermostat might be adjusting incorrectly. If your thermostat has an adjustable calibration scale, use it to adjust the heat anticipator. If this doesn’t work, replace the thermostat.
Not blowing hot air? Blower Motor Either the blower motor is burnt out, or the motor’s connect belt has snapped. See if power is reaching the motor. If it is, but the motor isn’t running, replace the motor. If the motor runs but air doesn’t move, the connecting belt has snapped. Replace the belt.
Blowing too much air? Control Board Your furnace’s blower motor is continually being sent voltage due to a failed relay on the control board. You will have to replace the control board.
Thermostat The contact that controls the blower motor on your thermostat may be sticking. Use a multimeter to check for continuity. If it appears the thermostat is the issue, replace the part.
Starting and then stopping shortly after? Flame Sensor The flame sensor detects if a flame is present. If it is either defective or dirty, it will not be able to detect a flame. If dirty, use a fine abrasive pad to clean the sensor. If faulty, replace the flame sensor.
Error Code What this means How to fix it
LED is steadily on Normal fault detected.
Single LED flash Failed to detect flame within three attempts for ignition, 1-hour lockout. Reboot system.
Two LED flashes The pressure switch is stuck open or induced draft blower problem detected. Try to manually close the switch, replace the switch, or check blowers and vents for air pressure.
Three LED flashes The limit switch is open, or the roll-out control is engaged. Check for a restricted air vent, loose blower wheel, a defective blower, or a dirty air filter.
Four LED flashes The pressure switch is stuck closed, or the switch won’t open. Check for an obstruction in the pressure tubing.
Five LED flashes N/A
Six LED flashes Line and Neutral are reversed. Control board or the furnace’s ground could be defective.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Your furnace’s fuse has blown, or the circuit breaker has shorted. Either reset the furnace’s circuit breaker or replace the blown switch completely.
Igniter Either the igniter is defective or cracked. Check to see if the igniter is cracked and replace it If it’s not, test it with a multimeter to see if it’s defective.
Cycling irregularly? Thermostat Your thermostat is likely not adjusting correctly. Use your thermostat’s adjustable calibration scale to adjust the heat anticipator. If this doesn’t work or isn’t an option, replace the thermostat.
Not blowing hot air? Blower Motor Your furnace’s blower mower may be completely burnt out, or the connecting belt may have snapped. If the blower motor is receiving power but isn’t running, replace the motor. However, if it does run, it’s more likely that the connecting belt has snapped, replace it.
Blowing too much air? Control Board The relay on the control board that regulates how much voltage is sent to the blower motor has failed. You will have to replace the control board.
Thermostat The thermostat contact that controls the blower motor function might be stuck in a closed position. You’ll have to use a multimeter to check for continuity if this appears to be the issue then replace the thermostat.
Starting and then stopping shortly after? Flame Sensor The flame sensor may not be able to sense the presence of a flame due to it being dirty or defective. If the flame sensor is dirty, use an abrasive pad to wipe it clean. If it’s defective, replace the flame sensor.
Error Codes What this means How to fix it
Heartbeat LED pattern on solid The control is locked out and will auto-reset after 1 hour. Reset power to clear the lockout.
Two LED flashes Pressure switch didn’t open. Obstructed pressure tubing; a pressure switch that’s stuck closed.
Three LED flashes The low-pressure switch did not close or has reopened. Proper vent sizing; air leak; restricted vent; clogged condensate drain; low input gas pressure; excessive wind; improper pressure switch wiring; water in vent piping; disconnected or obstructed pressure tubing.
Four LED flashes Limit circuit fault. Loose blower wheel; defective switch or connections; improper minimum- or maximum-heat gas input adjustment; dirty filter or restricted duct system; improper limit switch.
Five LED flashes Abnormal flame-proving signal. Leaky gas valve; stuck-open gas valve.
Six LED flashes Ignition proving a failure. Low inlet gas pressure; control ground continuity; gas valve defect; defective hot surface igniter; oxide buildup on the flame sensor; inadequate flame carryover; flame sensor mustn’t be grounded.
Seven LED flashes Limit circuit lockout. Control will auto-reset after 3 hours. Refer to status code #4.
Eight LED flashes Gas heating lockout. Gas valve stuck closed on control.
Nine LED flashes Medium pressure switch, high-pressure switch, or PSR relay didn’t close or was reopened. Refer to status code #3.
Ten LED flashes Polarity. Correct line voltage polarity.
Status codes 1 + 2 Blower on after power up. Normal operation.
Status codes 1 + 5 Blower motor lockout. Control will auto-reset after 3 hours. Refer to status code #4 + 1.
Status codes 3 + 5 Gas valve fault. RED, YELLOW, or ORANGE wire at the gas valve.
Status codes 4 + 1 Blower motor fault. Blower failed to reach 250 RPM, or the blower failed to communicate within the prescribed time limits.
Status codes 4 + 2 Inducer motor fault. Proper vent sizing; restricted vent; failed inducer motor; improper motor wiring; a blockage in the tubing to the pressure switch assembly.
Status codes 4 + 3 The low or medium pressure switch is open while the medium or high-pressure switch is closed. Low inlet gas pressure; clogged condensate drain; improper pressure switch wiring; water in vent piping; low or medium pressure switch stuck open; disconnected or obstructed pressure tubing.
Status codes 6 + 1 Ignition lockout. Control will auto-reset after 3 hours. Refer to status code #6.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Either the circuit breaker has shorted or the unit's fuse has blown. Reset the circuit breaker associated with your Coleman furnace. If it's still not heating correctly, you'll want to replace the fuse.
Igniter The igniter has cracked or become defective. Locate the igniter within your Coleman furnace and inspect the part for cracks. If it's damaged then you'll have to replace the part. Otherwise, test it with a multimeter for continuity to see if it's defective.
Cycling irregularly? Thermostat Your thermostat might be calibrated improperly and as a result, is adjusting incorrectly. Check to see if your thermostat has an adjustable calibration scale, if so then use this to adjust the heat anticipator. If this doesn't appear to work or you don't have a scale, replace the thermostat completely.
Not blowing hot air? Blower Motor The blower motor in your Coleman furnace is either burnt out or it's connecting belt has broken. You'll have to inspect the motor to see if power is reaching it. If it does but the motor continues to function incorrectly, then the blower motor has failed. However, if the motor continues to run, but the air still isn't moving, then the connecting belt has broken. Depending on the situation, you'll have to replace the motor or the belt.
Blowing too much air? Control Board The control board is experiencing difficulty. The board's relay that regulates how much voltage is sent to the blower motor is defective. You will have to replace the control board.
Thermostat The contact on your thermostat responsible for controlling the blower motor is defective. Use a multimeter to check for continuity, if the thermostat isn't working properly then replace it.
Starting and then stopping shortly after? Flame Sensor The flame sensor used to detect whether or not a flame is present requires attention. The sensor has become either dirty or defective. Use a fine abrasive pad to clean the sensor if it appears to be dirty. If it's defective then replace the sensor altogether.
Error Codes What this means How to fix it
Slow green flashing Coleman furnace is operating normally. N/A
Slow amber flashing Normal operation with a call for heat. N/A
Steady on red There's a control failure.
Rapid red flashing There's a twinning error with incorrect 24V phasing. Check the twinning wiring.
Rapid amber flashing There's a low flame sense current. Check and clean the flame sensor. If it's still an issue, check for proper gas flow.
One red flash A flame's present with the gas turned off. Check the gas valve. It could be leaky or slow closing.
Two red flashes Pressure switch is stuck in the closed position. Check if there is a faulty pressure switch or miswiring.
Three red flashes Pressure switch is stuck in the open position. Check if there is a faulty inducer, a blocked vent pipe, a broken pressure switch hose, or a faulty pressure switch.
Four red flashes Limit switch is stuck while open. Check for a a dirty filter, an improperly sized duct system, an incorrect blower speed setting, or a faulty blower motor.
Five red flashes Rollout switch is stuck while open. The rollout control is manually reset. Therefore, if it has opened, then check to see if the inducer is operating properly or there is an issue with the primary heat exchanger.
Six red flashes Pressure switch cycle has locked out. The furnace will lockout for one hour and then reset.
Seven red flashes There's an ignition lockout due to too many retries. The flame couldn't be established, check for a faulty gas valve, a dirty or defective flame sensor, a faulty hot surface ignitor, or a problem with the burner.
Eight red flashes There's an ignition lockout due to repeated power recycles. Check if there is low gas pressure, a dirty or defective flame sensor, or a faulty gas valve.
Nine red flashes There's a grounding or line polarity issue. Check the polarity at both the furnace and branch.
Ten red flashes Gas continues to flow with no call for heating. Check on the gas valve and the gas valve wiring.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Then either the circuit breaker has shorted, or the unit's fuse has blown completely. You'll have to reset the circuit breaker that connects to your furnace. If this doesn't help, then it's likely the fuse has blown, and you'll have to replace it.
Igniter The igniter is either defective or cracked. You should locate the igniter within your Goodman furnace and check the part for cracks. If it's cracked then replace the part, but it isn't then you'll have to test it with a multimeter for continuity to see if it's defective.
Cycling irregularly? Thermostat Your thermostat might be adjusting incorrectly. If your thermostat has an adjustable calibration scale, use this to adjust the heat anticipator. However, if this doesn't appear to work or you don't have a scale, you should replace the thermostat altogether.
Not blowing hot air? Blower Motor Your furnace's blower motor has either burnt itself out, or the connecting belt has snapped. You should check to see if power is reaching the motor. If it does but the motor isn't running, then the blower motor has failed. Alternatively, if the motor does run, but the air still doesn't move, then the connecting belt has snapped. Either replace the motor or belt depending on the situation.
Blowing too much air? Control Board The relay on your control board that regulates the voltage sent to the blower motor has failed. Should this occur, you'll have to replace the control board entirely.
Thermostat The contact on your thermostat that controls the blower motor is closed. You should use a multimeter to check for continuity. If the thermostat is functioning improperly, replace it altogether.
Starting and then stopping shortly after? Flame Sensor Your furnace uses a flame sensor to detect if a flame is present. If this sensor is defective or dirty, it will be unable to detect a flame. You should use a fine abrasive pad to clean the sensor if it's dirty. Otherwise, you can replace the flame sensor entirely.
Error Code What this means How to fix it
Single LED flash, steadily on This means your Goodman furnace has no signal coming from the thermostat and won't operate. You should check your thermostat for an improper setting or connection.
Single LED flash, blinks on and off This means that your furnace has locked out due to too many ignition attempts. After one hour of lockout, your furnace will automatically reset itself.
Two LED flashes This means that the draft blower isn't functioning properly, or your furnace has a short in the pressure switch circuit. You should either repair the short or replace the pressure switch.
Three LED flashes This means your furnace has an open pressure switch circuit or the induced draft blower is operating when it shouldn't be. You should check the pressure switch hose for blocks or an improper connection. Otherwise, see if any loose wiring needs tightening.
Four LED flashes This means your furnace has a primary open limit circuit. You should check and clean all the filters, tighten the wiring, and see if there are any blockages in the flue.
Five LED flashes This means that your furnace senses a flame without a call for heat. You should check for a leaky or open gas valve or a lingering burner flame.
Seven LED flashes This warns of a low flame sense microamp signal. This is the result of a coated flame sensor or a lazy flame due to poor gas pressure. Adjust the gas pressure according to the information available to you.
Eight LED flashes This means your furnace has an igniter circuit problem due to a defective igniter or an improperly connected igniter. Replace the igniter or check the ground wiring for defects.
Nine LED flashes This means that your furnace has a high-stage pressure switch that won't close during a high-stage-induced draft blower operation. Check your Goodman furnace for a pinched or blocked pressure switch hose.
Continuous LED flashes This means that your furnace has a reversed polarity of 115 volts. You will have to correct the wiring polarity after reviewing the wiring diagram.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Either the furnace's electrical system has shorted, or the power switch has blown. To fix this, you'll have to reset your furnace's circuit breaker. However, if the switch has blown, you'll have to replace it.
Igniter The igniter in your furnace is either cracked or defective. Check the igniter for cracks, if you find some then you'll have to replace it. Otherwise, test the igniter with a multimeter for continuity to see if it's defective.
Cycling irregularly? Thermostat The furnace's thermostat is adjusting incorrectly. If your thermostat has an adjustable calibration scale, use it to adjust the heat anticipator. If this doesn't work or you don't have a scale, you should replace the thermostat altogether.
Not blowing hot air? Blower Motor The furnace's blower motor has either burnt out or is running improperly. If you notice that power's reaching the motor but it still isn't operating, you'll have to replace it. However, if it runs but the air doesn't move, the connecting belt has broken. You should replace the belt.
Blowing too much air? Control Board The furnace is sending an improper amount of voltage to the blower motor due to a failed relay on the control board. You should replace the control board.
Thermostat The contact that controls the blower motor on your thermostat is stuck. You should use a multimeter to check for continuity. If it isn't operating correctly, you'll want to replace the thermostat.
Starting and then stopping shortly after? Flame Sensor Your furnace's flame sensor is either dirty or defective. This means that it's unable to sense whether a flame is present. You should use an excellent abrasive pad to clean the sensor if it's dirty. If it isn't dirty, you must replace the flame sensor entirely.
Error Code What this means How to fix it
Slow green flash This is normal operation. N/A
Slow amber flash This is normal operation with a call for heat. N/A
Rapid red flash This is a twinning error, incorrect 24V phasing. You should check the twinning wiring.
Four amber flashes The control is receiving a "Y" signal from the thermostat without a "G" signal, and this indicates that the thermostat is wired incorrectly. You should check the thermostat wiring.
One red flash Flame sensed when there was no call for heat. You should check for a leaky or slow closing gas valve.
Two red flashes The pressure switch contacts that are normally open are stuck in the closed position. You should check for a faulty pressure switch, miswiring, or an open pressure switch contact that didn't close after the inducer was energized.
Three red flashes Many issues could cause this. Check for a faulty inducer, blocked vent pipe, broken pressure switch hose, or a faulty pressure switch.
Four red flashes The contacts on the main limit switch that are normally closed have opened. You should check for a dirty filter, an improperly sized duct system, an incorrect blower speed setting, an incorrect firing rate, or a faulty blower motor.
Five red flashes The contacts that are normally closed have opened during the rollout switch. The rollout control is manually reset. If it has opened, you should check to see if there's a proper supply of combustion air. Otherwise, you can inspect the inducer's operation, the primary heat exchanger for a sign of failure, or the burner for potential issues. Remember to reset the switch and cycle power to the control.
Six red flashes After the unit began operating, the pressure switch opened four times during the call for heat. The furnace will lockout for 1 hour and then restart.
Seven red flashes The flame could not be established. The no-light condition occurred three times during the call for heat before locking out. You should check for low gas pressure, a faulty gas valve, a dirty or defective flame sensor, a faulty hot surface ignitor, or the burner for potential issues. The furnace will lockout for 1 hour and then restart.
Eight red flashes The flame has been lost five times during the heating cycle. You should check the system for low gas pressure, a dirty or faulty flame sensor, or a defective burner. The furnace will lockout for 1 hour and then restart.
Nine red flashes The line voltage polarity has been reversed or there's a grounding problem. You should check the furnace grounding and the polarity at both the furnace and branch.
Ten red flashes A flame has been sensed with no call for heat. You should check the gas valve as well as the gas valve wiring.
Eleven red flashes This is usually caused by a failed blower motor or blower wheel. After correcting the failure condition, you will want to cycle power to the control which will reset the hard lockout condition.
Twelve red flashes This indicates an open igniter circuit. You should check for a disconnected or loose wire, or a cracked or broken igniter.
Steady red This is a control failure. You should replace the control board.
Is your furnace... The problem might be your... What's wrong? How you can fix it:
Not heating? Circuit Breaker/Fuse Your furnace either has a blown fuse or a shorted circuit breaker. Reset your furnace’s affiliated circuit breaker or replace the blown switch entirely.
Igniter The furnace’s igniter has either cracked or is now defective. Check to see if the igniter is cracked. Replace it if it is. If the piece isn’t cracked, test it with a multimeter to see if it’s defective.
Cycling irregularly? Thermostat The thermostat is likely not adjusting correctly. Use the adjustable calibration scale on your thermostat to adjust the heat anticipator. If this doesn’t work or isn’t an option then replace the thermostat.
Not blowing hot air? Blower Motor There is likely an issue with your furnace’s blower motor. It could be burnt out, the wheel could be defective, or the connecting belt may have snapped. If the motor shows to be receiving power but is still not running then replace the blower motor. But, if it does run, you will likely have to replace either the connecting belt or the wheel.
Blowing too much air? Control Board Your control board isn’t functioning properly. The relay that regulates the blower motor’s voltage has failed. You will have to replace the control board.
Thermostat The contact that controls the blower motor function on your thermostat is stuck in a closed position. Use a multimeter to check for continuity, if this appears to be the issue then replace the thermostat.
Starting and then stopping shortly after? Flame Sensor Your furnace’s flame sensor isn’t able to sense the presence of a flame due to it being dirty or defective. Use a fine abrasive pad to clean to the sensor clean, if this doesn’t fix the issue then replace the flame sensor entirely.
Error Codes What this means How to fix it
Slow flashing LED light This means that your furnace is on, but it’s not calling for heat. This is only an issue if you have raised your thermostat and your furnace doesn’t respond.
Rapidly flashing LED light Means that your furnace is on and is actively calling for heat. Only beware this if your furnace is continuously calling for heat and isn’t responding to your thermostat.
Continuous LED on Control panel issue. Replace the control panel.
Two LED flashes System lockout due to lack of flame or reversed polarity. Check for miswiring, clogged pilot tube, or humidity in the unit.
Three LED flashes Draft pressure error. Check if the drain tubes are full of moisture or obstructed with dirt.
Four LED flashes The furnace is experiencing an open temperature limit circuit issue. The issue with thermal protection.
Five LED flashes A flame was sensed within your furnace that shouldn’t be present. Check for a leaky gas valve, stuck gas valve, or defective flame sensor.
Six LED flashes AC power voltage is too low. Correct line voltage polarity, check the wiring.
Seven LED flashes An issue with your gas circuit. Check your unit’s gas valves for the issue.
Eight LED flashes Low Flame. Check for flame sensor malfunction or low gas pressure.
Nine LED flashes Igniter circuit issue. Check igniter.
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