Provided there is no serious issue and you do everything on your own, air conditioner troubleshooting will cost you a few dollars (or nothing) and take very little time. To find out, whether this solution is possible in your case, check out the professional advice on air conditioner repair given by the manufacturer, Dublin-based company Trane Inc.
Trane 4MXW6-A air troubleshooting
| Problems | Possible causes |
| Air conditioner does not run upon immediately restart after a stop. | To protect the air conditioner upon immediate restart after a stop, the microcomputer controller will delay the unit for 3 minutes before the air conditioner will run. |
| Air conditioner blows out bad smell when it is initially started. | – The air conditioner itself has no bad smell. Solution: Clean the air filter. – If the problem persists after cleaning the filters, the air conditioner should be cleaned and serviced by an Authorized Trane dealer) |
| You may hear “Water Flowing” noise when the air conditioner is running. | When the air conditioner is started, or the compressor is started or stopped during running or the air conditioner is stopped, sometimes you may hear the flowing sound of refrigerant. |
| Sometimes a thin fog will flow out of the outlet when air conditioner is running under cooling mode. | This might occur when indoor temperature and humidity are high. This is because the indoor air is quickly cooled down. After a period of time, the fog will disappear with the decrease of indoor temperature and humidity. |
| You may hear a slight crack when the air conditioner is started or stopped. | This is the sound caused by expansion of plastic panel or other parts due to the change of temperature. |
| The unit can not run | – Has the power been shut down? |
| – Does power plug come loose from the socket? | |
| – Is the circuit protection device tripped off or not? | |
| – Is voltage higher or lower? (Tested by professionals) | |
| – Is the Timer correctly used? | |
| Cooling(Heating) efficiency is not good. | – Is Temp, setting suitable? |
| – Were inlet and outlet vents obstructed? | |
| – Is there too much dust accumulated and obstructed the filter? | |
| – Are the windows and doors closed? | |
| – Did Fan speed set at low speed? | |
| – Is there any heat sources in the room? | |
| Wireless remote control is not functioning | – Is it in its receiving range? Or obstructed? |
| – Check and/or replace the batteries. | |
| – The wireless remote control is damaged. | |
| Water leakage in the room | – The air humidity is on the high side. – Water overflowing due to blocked drain tube. Call your Authorized Trane dealer. |
| – The connection position of indoor unit drainage pipe is loose. | |
| Water leakage in outdoor unit | – When the unit is running in the COOL mode, moisture from the indoor space will be discharged from the drain pipe. |
| – When the unit is running in the HEAT mode, moisture may drip from the outdoor coil. | |
| – When the unit is running in Auto Defrost mode, frost that has formed on the outdoor coil will be thawed. | |
| Noise is emitted from the indoor unit. | – The sound of the fan or compressor relay switching on or off. |
| – When the defrost mode is starting or stopping, the sound of refrigerant flow changing direction may be heard. | |
| No air is being delivered from the indoor unit | – In the HEAT mode, if the temperature of the indoor coil is very low, the fan will stop for up to 3 minutes to prevent the delivery of cold air. |
| – In the HEAT mode, frost may accumulate on the outdoor coil due to low outdoor temperature and/or high outdoor humidity. The unit will automatically switch to defrost mode, and the indoor unit will stop blowing air for approximately 8-10 minutes. During the defrost cycle, moisture may flow from the outdoor unit and steam may be observed. | |
| – In the dehumidifying mode, the indoor fan occasionally stops to avoid condensing water to be re-vaporized. | |
| Moisture on the guide louver | If the unit is running for extended periods of time in high humidity conditions, moisture may accumulate on the guide louver. |
Trane FTXS18DVJU air troubleshooting
| Case | Explanation |
| Operation does not start quickly. • When ON/OFF button was pressed soon after operation was stopped. • When the mode was reselected. |
• This is to protect the air conditioner. You should wait for about 3 minutes. |
| Hot air does not flow out soon after the start of heating operation. | • The air conditioner is warming up. You should wait for 1 to 4 minutes. (The system is designed to start discharging air only after it has reached a certain temperature.) |
| The heating operation stops suddenly and a flowing sound is heard. | • The system is taking away the frost on the outdoor unit. You should wait for about 3 to 8 minutes. |
| The outdoor unit emits water or steam. | • In HEAT mode • The frost on the outdoor unit melts into water or steam when the air conditioner is in defrost operation. • In COOL or DRY mode • Moisture in the air condenses into water on the cool surface of outdoor unit piping and drips. |
| Mists come out of the indoor unit. | • This happens when the air in the room is cooled into mist by the cold airflow during cooling operation. |
| The indoor unit gives out odor. | • This happens when smells of the room, furniture, or cigarettes are absorbed into the unit and discharged with the airflow. (If this happens, we recommend you to have the indoor unit washed by a technician. Consult your authorized dealer where you bought the air conditioner.) |
| The outdoor fan rotates while the air conditioner is not in operation. | • After operation is stopped: • The outdoor fan continues rotating for another 60 seconds for system protection. • While the air conditioner is not in operation: • When the outdoor temperature is very high, the out door fan starts rotating for system protection. |
| The operation stopped suddenly. (OPERATION lamp is on) | • For system protection, the air conditioner may stop operating on a sudden large voltage fluctuation. It automatically resumes operation in about 3 minutes. |
| The air conditioner does not operate. (OPERATION lamp is off) | • Has a breaker been turned OFF or a fuse blown? • Is there a power failure? • Are fresh batteries installed in the remote controller? • Is the timer setting correct? |
| Cooling (Heating) effect is poor. | • Are the air filters clean? • Is anything blocking the air inlet or the outlet of the indoor and the outdoor units? • Is the temperature setting appropriate? • Are the windows and doors closed? • Are the airflow rate and the air direction set appropriately? |
| Operation stops suddenly. (OPERATION lamp flashes.) | • Are the air filters clean? • Is there anything blocking the air inlet or the outlet of the indoor and the outdoor units? Turn the electrical breaker off, clean the air filters or remove obstacles away from inlet and outlet. Then turn the breaker ON again and try operating the air conditioner with the remote controller. If the lamp still blinks, call your authorized dealer where you bought the air conditioner. |
| An abnormal functioning happens during operation. | • The air conditioner may malfunction with lightning or radio waves. Turn the circuit breaker OFF, to reset unit. Then turn it ON again and try operating the air conditioner with the remote controller. |
Trane MCC 518 ZB air troubleshooting
| Problem | Causes |
| No operatio | • Check if electrical wire is damaged & check if breaker switch is still on. |
| • Check if the power supply is in order. | |
| • Check if the timer switch is on or not. | |
| The air conditioner runs but does not cool enough. | • Check if the preset temperature is too high. |
| • Check if the sunlight shines directly into the room. | |
| • Check if the door and window are opened. | |
| • Check if there is anything obstructing the air discharge. | |
| • Check if the exhaust fan still operates. | |
| • Check if the air filter is dirty or clogged. | |
| Vapor or mist fume coming out of the unit while running. | • Hot air in the room mixes with cool air. This causes smoke fume. |
| Inoperative remote control. | • Loosened or disconnected wire between the unit and the remote controJ |
| • Check if the batteries are inserted in correct directions. | |
| • Check if the batteries are exhausted or not. |
Trane R410a air troubleshooting
| Symptom | Remedy |
| Indoor unit does not give cool air immediately when unit starts. | Compressor restarts after approximately three minutes to protect itself. On compressor restarting units starts to give cool air again |
| Unusual odor blowing from outlet when unit is started. | Open the door or window for 2 minutes and run the AC in Fan mode to allow fresh air inside the room. This helps to remove odors from inside the room. |
| Sound of water flow during operation. | This is caused by refrigerant flowing inside the unit. |
| Formation of mist while cooling. | Room air is cooled quickly by cold air flow which looks like fog. |
| Creaking noise during start or stop. | Deformation of plastic because of temperature change. |
| Unit does not operate. | Check electrical system connections, cords and fuses. |
| Check if power supply is within + 10% of rated supply. | |
| Decreased cooling efficiency. | Check ‘set temperature’. |
| Check for obstructions in air inlet and outlet. | |
| Check air filters for dirt. | |
| Check indoor fan speed. | |
| Check any other openings in the room. | |
| Remote control does not work correctly. | Check effective distance to indoor unit. |
| Check low battery error indication on remote display. |
Trane 190 air troubleshooting
| Problems symptoms | Problem cause | Action recommended |
| A) The compressor does not start up | ||
| Compressor terminals are live but motor does not start | Motor burned out. | Replace compressor |
| Contactor motor not operational. | Coil burned out or broken contacts. | Repair or replace. |
| No current ahead of motor contactor. | a) Power cut. | Check fuses and connection. |
| b) Main power supply switched off. | If system is operational, switch on main power supply. | |
| Current ahead of fuse, but not on contactor side. | Fuse blown. | Check motor insulation. Replace fuse. |
| Low voltage reading on voltmeter. | Voltage too low. | Contact power Supply Utility. |
| Starter coil not excited. | Regulation circuit open. | Locate regulation device which has tripped out and see why. Replace compressor. |
| Compressor does not run. Compressor motor “groans”. High pressure switch tripped to contacts open on high pressure. Discharge pressure too high. |
Compressor sticking (damaged or sticking components). Discharge pressure too high |
|
| B) Compressor stops | ||
| High pressure switch tripped. | ||
| Over current thermal relay tripped. | Discharge pressure too high. | |
| a) Voltage too low. | a) Contact Power Supply Utility. | |
| b) Cooling demand too high, or condensing temperature too high. | ||
| Motor temperature thermostat tripped. Anti-freeze security tripped. | Not enough cooling fluid. | Repair leak. Add refrigerant. |
| C) Compressor stops just after its start | ||
| Suction pressure too low. Filter drier iced up. | Filter drier clogged. | Replace filter drier. |
| D) The compressor keeps running without stopping | ||
| Temperature too high in areas requiring air- conditioning. | Excess load on cooling system. | Check thermal insulation and air-tightness of areas requiring air-conditioning. |
| E) Loss of oil in compressor | ||
| Oil level too low in indicator. | Not enough oil. | Contact Trane office before to order oil |
| Gradual fall in oil level. Suction line too cold. Compressor noisy | Filter drier clogged. | Replace filter drier. |
| Liquid flows back to compressor. | Adjust superheat and check bulb fixing of the expansion valve. | |
| F) Compressor noisy | ||
| Compressor knocks. | Components broken in compressor. | Change compressor. |
| Suction line abnormally cold. | a) Uneven liquid flow. | a) Check superheat setting and fixing of expansion valve bulb. |
| b) Expansion valve locked in open position. | b) Repair or replace. | |
| G) Insufficient cooling capacity | ||
| Thermostatic expansion valve “whistles”. | Not enough refrigerant. | Check refrigerant circuit tightness and add refrigerant. |
| Excess pressure drops through filter drier. | Drier filter clogged. | Replace. |
| Excessive superheat. | Superheat not properly adjusted. | Check adjustment of superheat and adjust thermostatic expansion valve. |
| H) Discharge pressure too high | ||
| Condenser abnormally hot. | Presence of uncondensable liquids in system, or excess refrigerant. | Purge uncondensable fluids and drain off excess refrigerant. |
| Condenser air output too hot. | Reduced air flow. Air intake temperature higher than specified for unit. | Clean battery. |
| Check operation of motor fans. | ||
| I) Suction pressure too high | ||
| Compressor operates continuously. | Excess cooling demand on evaporator. | Check system. |
| Suction duct abnormally cold. Refrigerant flows back to compressor. | a) Expansion valve too far open. | a) Check for superheat and check that expansion valve bulb is secure. |
| b) Expansion valve locked in open position. | b) Replace. | |
| J) Suction pressure too low | ||
| Excessive pressure drop through filter drier. Refrigerant does not flow through thermostatic expansion valve | Drier filter clogged. Expansion valve bulb has lost its refrigerant. |
Replace the deshydrator. Replace the bulb. |
| Loss of power. | Expansion valve obstructed. | Replace. |
| Superheat too low. | Excessive pressure drops through evaporator. | Check adjustment of superheat and adjust thermostatic expansion valve. |