What You Can Safely Check Before Calling an HVAC Technician

Safe pre-call checks are limited to observations that do not open equipment, touch energized parts, handle refrigerant, or enter unsafe spaces.

Direct Answer

Check thermostat mode and setpoint, filter condition, supply and return registers, breaker position without repeated resetting, visible standing water, visible outdoor blockage, visible error code, sounds, and smells.

When To Stop

Stop and call for recurring breaker trip, water near equipment, frozen coil or lines, repeated drain backup, electrical smell, loss of airflow, fault codes, unexplained auxiliary heat, or suspected refrigerant, combustion, or loop problem.

Emergency Boundaries

Gas odor, smoke, fire, carbon-monoxide alarm, exposed wiring, flooding near electrical equipment, suspected refrigerant exposure in a confined space, or unsafe attic, crawlspace, drilling, or well conditions require immediate safety action.

What A Professional Measures

A professional may measure voltage, amperage, capacitance, airflow, static pressure, temperature split, combustion, drain safety, refrigerant circuit behavior, and geothermal loop flow or temperature.

Related Hartzell Pages

• HVAC Troubleshooting Guide
• Common HVAC Problems
• Electrical Safety
• Emergency HVAC

Common Questions