HVAC systems often show small warning signs before a bigger issue happens, such as weak airflow, uneven temperatures or higher energy bills. A service visit often begins with basic checks, then moves into thermostat testing. If the system is not performing well, troubleshooting may look at refrigerant related performance. Regular heating system tune-up can help reduce surprise breakdowns by addressing worn parts early and keeping coils and filters cleaner. Homeowners may also consider HVAC effic...