HVAC maintenance log and symptom worksheet

System profile

Item	Notes
System type	Furnace / heat pump / central AC / mini split / boiler / other
Brand and model
Approximate age
Filter size and type
Thermostat model
Outdoor unit location
Indoor equipment location
Last professional tune-up
Warranty or service plan

Monthly homeowner log

Date	Filter checked or changed	Thermostat setting	Unusual sounds	Uneven rooms	Outdoor unit clear	Notes

Symptom-to-observation worksheet

Do not use this section to diagnose unsafe equipment. Use it to describe what you noticed before calling a technician.

Symptom	What to record	Possible next step
Weak airflow	Which rooms, supply vent temperature, filter condition, closed dampers	Check the filter and obvious blocked vents; call a pro if airflow stays weak
AC running but not cooling	Indoor temperature, outdoor temperature, runtime, ice on lines, dirty filter	Turn the system off if ice is visible; call a technician
Furnace short cycling	How often it starts and stops, filter age, thermostat location	Check the filter; call a technician if cycles continue
Musty smell	First room noticed, drain pan area, recent humidity	Check visible moisture; review indoor air quality guidance
Burning or electrical smell	When it appears, whether breakers trip	Shut the system off and call a professional
Carbon monoxide alarm	Alarm location and time	Leave immediately and call emergency services

Seasonal service notes

Spring cooling prep

• Replace or clean the air filter.
• Clear leaves, grass, and debris from around the outdoor unit.
• Confirm supply and return vents are open and unobstructed.
• Run the cooling system before the first heat wave and record unusual noise or odor.
• Schedule professional service if cooling performance is weak, ice appears, or the system has not been inspected recently.

Fall heating prep

• Replace or clean the air filter.
• Test the thermostat in heat mode before the first cold spell.
• Confirm carbon monoxide alarms are installed and working in homes with fuel-burning equipment.
• Record delayed ignition, rumbling, soot, or unusual odor.
• Schedule professional service for combustion, venting, gas pressure, heat exchanger, and electrical checks.

Professional visit record

Date	Company or technician	Reason for visit	Findings	Parts replaced	Recommended follow-up

When to call a professional promptly

• No heat during freezing weather or no cooling during dangerous heat.
• Repeated breaker trips, burning smells, or visible damaged wiring.
• Any suspected gas leak, combustion problem, or carbon monoxide alarm.
• Ice on refrigerant lines or the outdoor unit in cooling mode.
• Water around indoor equipment that keeps returning.
• A system that starts and stops repeatedly after the filter has been checked.