Lennox Air Conditioner Troubleshooting Guide

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Common Problems with the Lennox Air Conditioner

Problem Possible Causes Solutions
AC is Not Cooling Obstruction of air circulation. Clean the filter, remove debris, and remove any obstructions from the vents.
AC is Noisy Various causes: Blower motor problems; Fan issues; Refrigerant leak; Etc. Identify the cause of the noise, and troubleshoot.
AC is Not Working Power supply problems. Contact a professional to fix the issue.

#1 Air Conditioner is Not Cooling Properly

If your AC unit is working, but is not delivering cool air into the room, the problem lies with air circulation around the unit. Your air vents may be obstructed by large pieces of debris, furniture, or walls that are preventing the warm air from escaping your unit, circulating back into the room.

Alternatively, the air filter may be dirty, which traps the cold air inside your unit. When this happens, you may have frozen AC coils, which can damage your evaporator coils over time. Turn off the air conditioner, take out the filter to clean it with soap and water, and let the indoor unit thaw out if necessary.

#2 Air Conditioner is Noisy

Aircon noises are some of the common issues for older units, particularly ones that have gone through years of wear and tear from regular use. A noisy air conditioner is most likely due to the fan blades hitting against another component, a busted fan motor, or the compressor starting to fail. Determine the cause of the noise by the sound your Lennox AC unit makes.

A clunking, banging, or otherwise hitting noise indicates a problem with the fan blades, or a loose part in your Lennox air conditioner unit. A helicopter-like noise or a loud, whirring sound would indicate problems with the fan motor, condenser, compressor, or capacitor. Other sounds may mean other issues:

  • Clunking or banging sound - Loose parts in air conditioning unit; Bent fan blades
  • Low buzzing or humming sound - Compressor issues
  • Screeching or squealing sound - Fan motor issues
  • Helicopter-like or whirring sound - Issues with blower motor, condenser, compressor, or capacitor
  • Clicking sound - Relay switch issues

#3 Air Conditioner is Not Working

If your Lennox air conditioners are not working at all, the problem is most likely with the power source and not the air conditioning system itself. You may have a power cut or black out, or problems with the breaker box. Check the circuit breaker box for a tripped breaker, busted fuse, or other electrical problems.

If you're experiencing electrical problems, contact a licensed electrician to fix the issue. Do not attempt to fix any electrical wiring yourself, especially if you do not have the experience working with wiring.

If the issue lies with your Lennox aircon units, however, contact us at Luce Aircon so we can properly diagnose and repair the issue for you. Our technicians can fix both single-stage and two-stage air conditioner models!

How to Reset Your Lennox Air Conditioner

Reset Point: Circuit Breaker

To reset your Lennox AC unit, power your AC unit off, but keep your unit plugged in to the electrical socket. Head to the circuit breaker box, and locate the circuit breaker that connects to your unit. Flip the switch to restart the circuit breaker, then wait for 30 seconds before flipping the switch back to its original position. This action should reset your Lennox AC.

Lennox Air Conditioner Solutions and Troubleshooting Guide

#1 Clean Your Unit

Cleaning your unit is your first step in troubleshooting, as most aircon issues can be fixed with a thorough cleaning of the air filter, the aircon coils, and the aircon vents. Clean both the indoor and outside unit to keep your AC working properly, and stick to a cleaning routine at least every 2 weeks.

#2 Check for Broken Fan Blades

For older models, check the fan blades for signs of wear and tear. You can easily reset a bent fan blade by gently but firmly bending it back into place, but if you are inexperienced with DIY troubleshooting, it is best to contact one of our Luce Aircon technicians to fix the problem for you. Check the owner's manual for a guide to troubleshooting your AC unit.

#3 Contact Luce Aircon for Maintenance and Repairs

Any repairs or replacement with the internal parts of the air conditioner should be done by a licensed technician. At Luce Aircon, we take steps to train and provide our technicians with the experience in handling different aircon models and brands across Singapore, so you can be sure we'll get the job done right!

Common Error Codes

Error Code Meaning
E0 EEPROM parameter error
E1 Indoor/outdoor units communication protection
E2 Zero-crossing signal error
E3 Indoor fan speed out of control
E5 Open or short circuit of outdoor temperature sensor or outdoor unit EEPROM parameter error
E6 Open or short circuit of room or evaporator temperature sensor
E7 Outdoor fan speed out of control
P0 IBM malfunction or IGBT over-strong current protection
P1 Over voltage or too low voltage protection
P2 Temperature protection of compressor top

Maintaining Your Lennox Air Conditioner

Regular maintenance is the key to preserving the good condition of your air conditioners, even your Lennox aircon. Home cleaning is not enough to keep your unit in tip top condition - your AC will need a checkup and maintenance at least once every 6 months to keep it in shape.

Check out our article on Gree aircon error codes.

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