When troubleshooting an HVAC unit, what is the first step to take?

In troubleshooting an HVAC unit, the first step is to verify the power supply and circuit connections. This is crucial because any issues related to power can prevent the HVAC unit from operating altogether. If there is no power to the system, it will not respond, regardless of the refrigerant levels, cleanliness of filters, or condition of ductwork. Ensuring that the unit is receiving the proper voltage and current allows for further troubleshooting steps to be taken effectively.

Once the power supply is confirmed, technicians can then move on to other checks, such as inspecting refrigerant levels, cleaning filters, or checking ductwork, which are also important but can only be effectively addressed if the unit has power. This systematic approach helps to isolate and resolve the issue efficiently, preventing unnecessary work or repairs that might arise from moving on to other aspects of the system without first confirming the power supply.