HVAC maintenance checklist: what to do every season

Why HVAC maintenance matters

Your heating and cooling system is one of the most expensive pieces of equipment in your home. Regular care helps it run efficiently, last longer, and break down less often, usually during the hottest or coldest week of the year.

Every month

• Check the air filter. Hold it up to the light. If you can’t see through it, replace it.
• Keep vents and returns clear. Furniture, rugs, and curtains blocking airflow make the system work harder.
• Listen for changes. New rattles, squeals, or short cycling (turning on and off often) are early warning signs.

Spring (before cooling season)

• Clear the outdoor unit. Remove leaves, grass clippings, and debris. Keep about two feet of clearance on all sides.
• Rinse the condenser coil gently with a garden hose (power off first). Never use a pressure washer.
• Flush the condensate drain line with a cup of distilled vinegar to prevent clogs and water leaks.
• Test the AC on a mild day so you find problems before the first heat wave.
• Book an AC tune-up.

Fall (before heating season)

• Replace the filter.
• Test the heat and note any burning smell beyond the first few minutes (dust burning off is normal briefly).
• Check carbon monoxide detectors near bedrooms and the furnace. Replace batteries.
• Book a furnace or heat pump tune-up. Gas furnaces should have the heat exchanger and venting inspected.

Thermostat tips

• Replace thermostat batteries once a year.
• A programmable or smart thermostat can cut energy use by setting back temperatures when you are asleep or away.

When to call a pro right away

• You smell gas or your CO alarm sounds: leave the house and call your gas utility or 911.
• Ice on the refrigerant lines or indoor coil
• Water pooling around the indoor unit
• Breaker trips whenever the system starts
• Warm air from vents in cooling mode

If your system is more than 12 to 15 years old and needs frequent repairs, ask a pro to compare repair costs against a high-efficiency replacement. Rebates and tax credits may help.