Mini-split systems are designed to run continuously at low power to maintain the desired temperature in a room, unlike traditional HVAC systems that cycle on and off. However, if your mini-split system is constantly running and not maintaining the temperature, there could be several reasons for this issue. This comprehensive guide will provide you with a step-by-step approach to diagnose and fix the problem, ensuring your mini-split system operates efficiently.
Checking Refrigerant Levels
If the refrigerant level in your mini-split system is low, it may have difficulty maintaining the desired temperature, causing it to run continuously. To check the refrigerant levels:
- Locate the service ports on the outdoor unit of your mini-split system. These are typically located on the refrigerant lines.
- Use a refrigerant gauge set to measure the pressure in the system. Compare the readings to the manufacturer’s specifications to determine if the refrigerant level is low.
- If the refrigerant level is low, you will need to have a professional HVAC technician diagnose and fix any refrigerant leaks in the system. Attempting to recharge the system yourself is not recommended, as it requires specialized equipment and knowledge.
Troubleshooting Thermostat or Remote Control Issues
If the thermostat or remote control is not functioning correctly, it may cause the mini-split system to run continuously. To troubleshoot this issue:
- Check the thermostat or remote control settings to ensure they are set to the desired temperature and mode (cooling or heating).
- Verify that the thermostat or remote control is accurately reading the room temperature by comparing it to a separate thermometer.
- If the thermostat or remote control is not functioning correctly, you may need to replace the batteries or have the unit serviced by a professional.
Cleaning Air Filters and Coils
Dirty air filters or coils can restrict airflow and cause the mini-split system to work harder, running continuously to maintain the desired temperature. To clean the air filters and coils:
- Locate the air filters in the indoor unit and remove them.
- Use a vacuum cleaner or soft-bristled brush to gently clean the filters, removing any dust or debris.
- If the filters are excessively dirty, you may need to replace them with new ones.
- To clean the coils, you will need to access the indoor and outdoor units. Use a coil cleaning solution and a soft-bristled brush to gently remove any dirt or debris from the coils.
- Ensure that the coils are completely dry before reassembling the units.
Verifying Correct System Size
If the mini-split system is too small for the room, it may have to work harder to maintain the desired temperature, causing it to run continuously. To ensure the system is correctly sized:
- Measure the square footage of the room or area the mini-split system is intended to cool or heat.
- Refer to the manufacturer’s specifications to determine the appropriate system capacity (in BTUs) for the room size.
- If the current system is undersized, you may need to have a larger capacity mini-split system installed by a professional HVAC contractor.
Checking for Proper Installation
Improper installation of the mini-split system can lead to issues with its performance, causing it to run continuously. To ensure the system is installed correctly:
- Verify that the indoor and outdoor units are properly connected, with all refrigerant lines and electrical connections made according to the manufacturer’s instructions.
- Check that the system is level and securely mounted, with no obstructions to airflow around the indoor and outdoor units.
- Ensure that the condensate drain line is properly installed and draining correctly.
- If you suspect any issues with the installation, it’s best to have a professional HVAC technician inspect and correct the installation.
Diagnosing Compressor or Fan Motor Issues
A faulty compressor or fan motor can cause the mini-split system to run continuously. To diagnose these issues:
- Listen for any unusual noises or vibrations coming from the outdoor unit, which may indicate a problem with the compressor or fan motor.
- Use a multimeter to check the electrical connections and measure the amperage draw of the compressor and fan motor, comparing the readings to the manufacturer’s specifications.
- If the compressor or fan motor is not functioning correctly, you will need to have a professional HVAC technician replace the faulty component.
By following these comprehensive troubleshooting steps, you can effectively diagnose and address the reasons why your mini-split system is constantly running, ensuring it operates efficiently and maintains the desired temperature in your home.
References:
- Brand-New Mini-Split System. Why is the fan running when it doesn’t need to? – HVAC-Talk.com
- Mini-Split Running CONSTANTLY! 6 Reasons Why! – YouTube
- My new Daikin mini split runs continuously. Both the inside and outside fans are running all the time. – JustAnswer HVAC
- Why does my Carrier mini split heat stay on even when the room is hot? – Reddit
- What Should I Do If My Mini Split Runs All The Time? – The Heat Pump Store