HVAC Troubleshooting
Follow our interactive troubleshooting guide to find answers to your system’s problems.
Choose from a selection of common HVAC issues or pick your product for help with fixes you can try yourself.
Why Is My Mini-Split Not Cooling?
Did your mini-split stop blowing cold air in the middle of a heat wave? Don’t sweat it. Check out our mini-split AC troubleshooting tips to get your space cool again. We’ll include some DIY tasks and tell you when you need to find an HVAC professional offering ductless system repair services.
Before you call an HVAC company to say your mini-split is not working, check your w
all thermostat/controller or your mini-split remote control. Make sure the mini-split unit(s) in question are set to Cool. Ensure the temperature setting is several degrees below the room temperature. If you live with someone who is always cold, they may have changed the temperature settings.
Your mini-split system needs good airflow to operate effectively. Check the air filters and clean them, being careful to let them dry thoroughly before replacing them and restarting the air handlers. Go outside and check your mini-split heat pump. Remove any twigs, leaves, or other debris that might be clogging the air intake. Trim shrubs so they are two feet away from the unit.
If checking the thermostat settings and cleaning the filters didn’t resolve the problem, refrigerant issues could be to blame. Specifically, low refrigerant levels. Your mini-split air conditioner or mini-split heating and cooling system relies on the refrigerant cycle to cool or heat your home. When levels are low, the system struggles.
Low refrigerant is caused by a refrigerant leak. A leak can be caused by wear and tear, poor mini-split installation, or improper charging at installation. Whatever the cause, only a trained HVAC technician can find the leak, repair it, and recharge the system.
The evaporator coil inside the indoor unit can get covered with dust and dirt and freeze up. A frozen evaporator coil can also be the result of dirty filters or a refrigerant leak. If you have frozen coils, call for HVAC repair. Regular maintenance can help prevent dirty coils.
Your mini-split HVAC system has a lot of components that work together to provide you with energy-efficient heating and cooling. Eventually, some of these parts wear out or malfunction. When your ductless system isn’t working right and you’ve tried DIY troubleshooting without any improvement, it’s time to call in the professionals to diagnose and fix the problem.
Take care of your mini-split AC unit or ductless heating and cooling system and protect your investment. Clean the reusable filters on each mini-split air conditioning unit regularly to help prevent problems with your ductless HVAC system. Whether you have one mini-split AC unit in your garage or a multi-zone mini-split system to heat and cool your whole house, make filter maintenance a priority.
Why? Because dirty or clogged air filters can cause issues with your mini-split, including:
- Poor or no cooling
- Poor or no heating
- Water leakage
- Mold and mildew growth
- Musty smell
- System damage
In addition, keep the outdoor condenser unit clear of debris. Trim shrubbery or other plants to keep them at least two feet away from the unit.
Schedule professional ductless mini-split maintenance at least once a year for a cooling-only mini-split and twice a year for a ductless mini-split heating and cooling system - once before the cooling season and once before the heating season.
If your mini-split HVAC system is still under warranty, we recommend scheduling maintenance with the HVAC contractor you used to install the system. For optimal results, work with an HVAC company that has extensive experience with ductless heating and cooling systems.
During the maintenance visit, the HVAC technician should:
- Inspect and clean the outdoor ductless heat pump and the indoor ductless units.
- Ensure the ductless system operates effectively.
- Check for refrigerant leaks.
- Check electrical connections.
- Make minor repairs.
Are you a new homeowner or new to the area and not sure who to call? Read our blog on finding the right HVAC contractor near you.
Anne Fonda, Content Writer at Trane Technologies
A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.
She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.
Expert review by Kimberly Sexton, Senior Systems Engineer
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