The “off” button on your aircon is designed to shut down your unit, but if the fan keeps running, you may have an issue. Common causes include a broken relay switch, thermostat problems, or electrical faults.
In Singapore, where air conditioners are often used day and night, these issues can lead to higher electricity bills and unnecessary wear on the unit. Addressing the problem quickly ensures your aircon operates efficiently without driving up costs!
Why Does the Air Conditioner Fan Keeps Running When Turned Off?
Reason #1: Broken Thermostat
A faulty thermostat might be the reason your AC refuses to shut down, particularly if you have your air conditioner set to a timer.
In Singapore, where temperatures can soar above 30°C year-round, many homeowners set their ACs at very low temperatures, such as 18°C, to combat the heat. If the thermostat malfunctions, it may fail to recognize that the desired temperature has been reached, causing the AC to keep running unnecessarily.
We often find lots of our client have issues with their thermostat setting. If this also happens to you, you can contact Luce Aircon—the trusted Singapore HVAC company, to diagnose and fix the problem for you!
Reason #2: Short Circuit or Faulty Relay Switch
The relay switch is what switches the voltage of your AC unit on and off, and communicates directly with the thermostat and the AC unit itself. A fault in the relay switches can cause failures in the shutdown of the air conditioner, and a broken relay board is often caused by a short circuit or damage to your electrical wiring.
This issue is particularly common in our clients who live in older HDB flats in Singapore, where electrical wiring may be outdated or worn out due to the high humidity levels.
Reason #3: Inconsistent Mini-split Settings
Many Singaporean homes use mini-split air conditioning systems, especially in condominiums and newer HDB flats. If some units keep running when turned off, then you may have inconsistent settings on your units. You may have set the temperature control or timer differently in each unit, or settings may have been altered in the main control panel.
For example, if your living room AC is set to 25°C, but your bedroom unit is set to 18°C, the system might continue to operate to balance the temperature across all rooms. To ensure this doesn't happen, it is best to ensure all your mini-split AC units are set to the same temperature and operational mode to prevent continuous operation. Check the main control panel to synchronize the settings.
Reason #4: The fan is Switched On
Check if you have the fan setting switched on in your unit. Your air conditioner keeps running when turned off because the fan is set to continuously run despite not blowing cool air. In this case, your air conditioning unit is registering that your fan motor should keep running even when the cooling system is shut down.
Reason #5: Miscommunication with Control Panel
Another possibility is a miscommunication between your control panel or remote that keeps your air conditioner continuously running even when turned off. The air conditioning system may not read the command properly and will run continuously as it does not read an initiated shutdown procedure.
This is a common issue in Singapore’s commercial buildings with centralized AC systems. If your AC unit has an electronic control board, miscommunication between the control panel and the thermistors can cause the fan to keep running even after the cooling cycle ends.
Is It Normal for an AC to Run Constantly?
While it may seem convenient to have an air conditioner running continuously, you shouldn’t let it happen. Instead, you should be concerned when it happens, as an aircon that runs non-stop will cause several problems.
If the AC never turns off, it will reduce its cooling efficiency. It might struggle to maintain a stable temperature, making your home feel not as cold or still humid. Additionally, air conditioners in Singapore often already undergo heavy usage due to the tropical climate. The continuous operation can wear out internal components, leading to costly repairs or replacement.
Lastly, letting your AC run constantly will also cause higher energy bills. Singapore is known as one of the countries in Southeast Asia which have the highest electricity cost. Thus, a constant running AC can cause a significant spike in your monthly utilities.
Simple Troubleshooting Guide
When the AC keeps running when turned off, you can try these simple troubleshooting steps to see if you can resolve the issue by yourself.
Double-Check Thermostat Settings
First, you should double-check the thermostat settings and ensure that it is correctly set. If you’re using an outdated thermostat, it may not be accurately reading the room temperature. Many of our clients in Singapore now are switching to smart thermostats for better control and energy savings, You might want to do the same too!
Clean Air Filters
Dirty or clogged air filters can obstruct airflow and cause the AC to work harder, potentially leading to continuous operation. Especially in Singapore’s humid environment, dust and mold buildup is common. We always advise our clients to clean the air filters regularly to improve efficiency and air quality.
Check for Blocked Airflow
Blocked vents or dirty evaporator coils can also prevent the system from shutting down properly. If airflow is restricted, the AC might keep running to try and reach the desired temperature. Ensure there are no obstructions around your indoor and outdoor units.
Check for Frozen Coil
If your AC’s evaporator coil freezes due to insufficient airflow or refrigerant issues, it can cause the system to overwork and stay on. This is a common issue in Singapore’s weather, thus you should look for signs of frost or ice around the indoor unit.
Problem Still Persist? Contact Luce!
If your air conditioner fan keeps running when turned off, don’t ignore it. Whether it’s a faulty thermostat, electrical issue, or misconfigured settings, addressing the problem early can save you money and prevent bigger issues down the line.
Luce is your trusted partner in bringing you top-quality aircon services across various models and brands in Singapore. We'll get to the bottom of the issue, and repair your AC unit to be as good as new.
Give us a call today to schedule an appointment with one of our experienced HVAC professionals!
Check out our article on why aircon turns on and off!
