Navigating air conditioning or heat pump issues can be confusing and frustrating when your HVAC system malfunctions. It’s natural to feel overwhelmed and unsure of where to turn for help and answers. This article addresses common HVAC questions (FAQs) to provide clarity during these stressful times. Whether you’re dealing with a sudden breakdown, unusual noises, or fluctuations in temperature, understanding the underlying causes and finding reliable solutions will get your HVAC system back up and running smoothly.
Check out the most common HVAC questions below to keep your home comfortable all year-round.
Q1: The indoor unit of my ductless split air-conditioner drips water when I operate in cooling mode. What are the possible problems and solutions?
Answer: When the air-conditioner is operating, the moisture from the room is removed through condensation at the cooling coil of the indoor air conditioning unit. The condensed water then drips onto the drain pan that is located underneath the coil.
The water is then removed from the drain pan through the drain hose that runs from the indoor air conditioning unit to the outside of the house by gravity or a condensate pump into the drain. Extra PVC piping may be required to connect the drain hose to the drain.
Check the following regarding your air conditioning system if it is dripping water:
a) If the air conditioner unit is drained by gravity, check the drain pan to make sure its elevation is correct. It should be slightly sloped to enable the water to flow down and into the drain hose and discharge to the outside of the building.
b) If the air conditioning unit is drained using a condensate pump, make sure the pump is working. The condensate pump is an additional accessory on an indoor air conditioning unit that is installed deep in the building. When the distance to drain the water from the pan is too far, the pump provides the suction needed to remove the water from the drain pan.
c) The air conditioning unit’s drain hose may be stuck or dirty, preventing water from flowing out. Blow or use a vacuum to remove the blockage.
d) Take out and clean the air filters located at the return air of the indoor unit. Dirty air filters will restrict the air flow.
Q2: My air-conditioner is showing error codes E3, E4 etc. Timer light is blinking. What is the problem and solution to this HVAC question?
Answer: Every HVAC system manufacturer displays its unique set of error codes when there’s an issue with the air conditioner unit that requires fixing. These error codes are designed to indicate specific issues with the HVAC system, allowing users or technicians to quickly identify the problem and offer a solution.
For example, an error code E1 may indicate that there is insufficient refrigerant gas such as freon in the system and requires topping off. Error E2 may indicate the room sensor has been disconnected. Error E7 may indicate an issue with your thermostat.
Check the operating manual that comes with your HVAC system to look up error codes when they occur. With most HVAC system software, there is usually a table with a list of error codes and their associated problems and solutions.
If the error codes are not available in your manual, you’ll need to contact the dealer or manufacturer to obtain them for that specific model. Homeowners should keep in mind that regular maintenance of your HVAC system helps prevent common HVAC repairs.
Q3: I am using a R22 refrigerant system. Can I change the refrigerant to R410A?
Answer: No, each refrigerant has been designed to operate at a particular pressure during operation. These two refrigerants have different properties and are not interchangeable. Changing the refrigerant in your HVAC system may damage the compressor and other HVAC system components.
Q4: Can my inverter air-conditioner be converted to a conventional air-conditioner by changing the control board and rewiring the unit?
Answer: No, converting the air conditioner is not possible, as the inverter compressor can only be regulated using the specific control board provided by the manufacturer. Furthermore, all the operating conditions of the air conditioning system have been designed to function based on the inverter unit.
Q5: I Should I buy an inverter air-conditioner HVAC system?
Answer: DC Inverter air-conditioner is the latest technology in the market. It is energy-efficient and proven to save on energy bills, providing comfort to homeowners. The compressor speed can vary from low to high depending on the requirements of the load.
An inverter air conditioner may come with a higher initial cost compared to a standard air conditioning unit. It’s strongly advised to invest in one for its energy efficiency. You’re likely to recoup your investment through reduced utility bills over time.
Q6: In my country, the power supply is 220V AC. Can the DC inverter air conditioner still operate when the voltage dips to 150V AC?
Answer: Refer to the manufacturer’s manual for your HVAC system to determine the minimum operating voltage at which the air conditioning unit can still function. Some manufacturers have designed their control boards to enable HVAC equipment to work at a low voltage to compensate for this dip. Otherwise, the air-conditioner may not work.
Q7: Does an on-off type compressor draw the same amount of current when it automatically turns on after being off as it does during the initial start-up of the unit?
Answer: When the compressor switches from OFF to ON status, it draws a current known as in-rush current, which can be several times higher than the rated running current. However, the exact current drawn may vary each time the HVAC system’s compressor turns on, depending on the phase of the current at the moment of switching on.
You may notice your fluorescent light flickering when this occurs. This happens because the compressor draws a significant amount of energy from the power supply when it turns on, causing a voltage dip.
Q8: How do I reduce the in-rush current of the compressor during starting of an ON/OFF type of compressor?
Answer: Use a suitable soft starter that will drastically reduce the startup current of the HVAC system’s compressor motor. Electronic devices inside this device control the voltage and the phase angle of the motor.
The other conventional alternative is to use an auto-transformer starter to limit the in-rush current when starting the HVAC equipment compressor motor.Â
Q9: When I turn on the AC unit, it turns ON briefly, them immediately turns OFF, and then starts up again. What is the cause of this?
Answer: 1) The OFF timer could be set to turn off the AC unit after a certain duration, while the ON timer could be set to turn it back on again. This could explain why the AC unit turns on briefly and then turns off, only to start up again shortly afterward. These timers are often used to automatically control the operation of the AC unit based on preset schedules. If you’re unsure how to adjust or deactivate these timers, consult the user manual.
2) Another possible reason for the AC unit turning on and off quickly could be due to pressing the ON/OFF button on the remote control repeatedly in quick succession.
Q10: My split unit is a panasonic non-inverter air-conditioner and I have to deal with this. There is no output on the printed circuit board for the outdoor fan. Do you have any idea why?
Answer:Â Usually for a non-inverter air conditioner, the outdoor unit fan is connected with the compressor. That means the outdoor fan will only operate when the compressor is running.
Q11: Here are my HVAC system questions: (1) In a domestic split-type A/C unit, will the inverter electronic components be vulnerable to heat and humidity inside the outdoor unit? (2) The volume and weight for the inverter outdoor unit is far less than that of a non-inverter type machine. Why is this so?
Answer:Â 1) An ideal outdoor unit design should protect the electronics against water and humidity. Some manufacturers will use coatings on the printed circuit boards or the HVAC system to prevent moisture and water from entering the parts. Make sure that the components are properly sealed after HVAC repair work is done.
2) The inverter compressor, despite having the same capacity, is lighter than the non-inverter type due to its higher efficiency. However, the inverter type requires more electronic controls.
Q12: I found out that my A/C(Panasonic CS-S13PKH) automatically switches to the timer mode. It shows H11 code. According to the model’s error code table, there is a communication error from the indoor air conditioning unit and outdoor unit. I showed it to a technician. He suspected the transistors in the outdoor PCB may be damaged but is unsure. How can I solve the problem?
Answer: This air conditioning unit is an inverter unit. Based on the symptoms you described, here are the potential problems that could be causing the issue:
1) The communicating cable between the indoor air conditioning unit and the outdoor unit is loose or disconnected.
2) The I-integrated circuits (IC) transistors, resistors, or other components that are related to the communication between both PCBs are damaged. The damage may occur in the indoor PCB, outdoor PCB, or both PCBs. Disconnect the power before checking the PCBs to prevent electrical shock. Consult a qualified technician if you are unsure.
Inspect the PCBs for burnt marks around the communication parts. This might be challenging to identify if you’re not familiar with electronics. If everything appears normal, consider removing the communicating components like transistors or ICs and examining them with a multimeter to make sure they’re still in good condition.
3) The electrical noise from other sources of the PCBs or surrounding circuits may have affected the communication lines between the indoor and outdoor PCBs. Proper shielding or noise filtering may be required. Seek professional assistance from a service provider in this instance.
Q13: Why did ice build-up on the coil of my indoor air conditioning unit in my split air conditioner?
Answer: There are several potential reasons for this issue with your air conditioning unit. It could be due to a dirty air filter or evaporator coil, which can restrict airflow. The other reason could be the blower fan on the AC unit is not functioning.
Another potential cause could be a low refrigerant charge. Additionally, low outdoor temperatures may contribute to this issue.
Q14: I have a ductless split AC unit. Why is my indoor air conditioning unit fan noisy?
Answer: The indoor air conditioner unit contains a blower fan, typically cylindrical and made of plastic. This fan draws air through the cooling coil and disperses cool air into the room. The fan assembly in your AC unit may be loose from many years of operation, causing the blower in your air conditioner to become unbalanced and noisy.
To solve the problem, the blower fan assembly needs to be taken up and any imbalance fixed. The motor shaft that is connected to the blower needs to be checked to make sure it is firmly secured.
Q15: Why is my indoor fan working but the compressor cannot turn on? Mine is a ductless split non-inverter cooling unit.
Answer: Possible legitimate issues include faulty printed circuit boards, compressor failure, faulty sensors, or wiring issues. If the manufacturer has built-in error codes, you can check them by observing blinking intervals or display indicators. Refer to the HVAC system manual to determine the type of fault indicated by the error code.
The possible non legitimate issues could be that the thermostat temperature setting is higher than the room temperature, so no cooling is necessary. In this scenario, the compressor doesn’t need to activate. If this is the situation, adjust the thermostat setting to be at least 3°C lower than the room temperature, and observe whether the AC system starts running.
Certain manufacturers of HVAC systems have a specific operation in DRY mode, where the compressor cycles on for a set period and then off for another. Switch the mode to COOLING mode instead.
Addressing common heat pump and cooling system issues can alleviate concerns homeowners have about their HVAC systems. While troubleshooting can resolve some issues, recognize when professional HVAC repair help is needed. Service contractors are equipped with the expertise to diagnose and fix complex problems. Regular maintenance is essential for prolonging the lifespan of HVAC systems and preventing costly HVAC repairs. I recommend homeowners stay proactive and seek professional assistance as needed.
