HVAC field checklist
HVAC error code checklist
Use this before ordering parts or booking service. Match the exact model
number, verify the simple checks, then price the likely parts.
Before you reset it
- Record the displayed code before cycling power.
- Check filter, thermostat call, breaker, disconnect, condensate switch, and door switch.
- For ignition faults, inspect flame sensor, igniter, rollout switch, pressure switch tubing, and venting.
- For cooling faults, inspect the run capacitor, contactor, condenser fan, and coil condition.
Parts worth pricing
When to stop
Stop and call a licensed HVAC tech for gas odor, repeated rollout trips, burned wiring, refrigerant work, or any fault that returns after reset.