Describe the heating problem
Note whether the furnace does not start, starts then stops, or runs while rooms remain cold. Record thermostat settings and any displayed error code without removing service panels. Tell the technician about recent filter changes or work near the system.
Put safety before troubleshooting
A suspected gas leak or carbon monoxide alarm is not a routine service request. Leave the building and contact emergency services or your gas utility from a safe location. Do not try to find or repair a gas leak. This website does not monitor emergency requests.
Questions for the diagnosis
Ask the provider to explain the failed component and why it needs repair. Separate diagnostic charges from labor and materials. Confirm whether venting, controls or airflow need further evaluation and ask which findings affect safe operation.
Make the repair scope clear
A written estimate should identify the equipment, repair, exclusions and warranty on the work. Ask whether parts are available and what happens if the diagnosis changes. If replacement is recommended, request an itemized alternative so that installation work is not confused with the equipment price.
Common questions
Should I keep resetting a furnace?
Follow the manufacturer’s instructions and stop repeated reset attempts when a fault returns. Arrange professional assessment.
Is a repair visit a replacement quote?
They are different scopes. Ask the provider whether the visit includes diagnosis, a written repair estimate, a replacement assessment or separate charges for each.
Further reading: ENERGY STAR heating and cooling guidance. This page is a planning resource, not an equipment diagnosis.