HVAC maintenance schedule
How often should I service my HVAC system and what does maintenance include?
Projekt-Plan
Why: Clogged filters restrict airflow, forcing the system to work harder, increasing energy bills and risking motor failure.
How:
- Locate the filter slot (usually near the return air duct or furnace).
- Check the size printed on the side (e.g., 20x25x1).
- Use a MERV 8 to MERV 11 filter for a balance of filtration and airflow.
- Insert the new filter with the arrow pointing toward the unit.
Done when: A clean, correctly sized filter is installed and the date is written on the frame.
Why: Leaves, grass clippings, and dirt can block heat transfer, causing the compressor to overheat.
How:
- Maintain a 2-foot (60 cm) clearance around the unit.
- Trim back shrubs or overhanging branches.
- Remove any trapped leaves or twigs from the base of the unit by hand.
Done when: The area around the outdoor unit is clear of all vegetation and debris.
Why: Algae and mold can clog the drain line, leading to water damage in your home or a system shutdown.
How:
- Locate the PVC drain pipe near the indoor unit.
- Remove the cap and pour about 1 cup of distilled white vinegar down the line to kill growth.
- If standing water is present, use a wet/dry vacuum to suck out the clog from the outside exit point.
Done when: The drain line is clear and vinegar has been applied to prevent future growth.
Why: Dirty coils reduce the system's ability to release heat, significantly lowering cooling efficiency.
How:
- Turn off the power at the outdoor disconnect box.
- Use a garden hose with a gentle spray (never a pressure washer) to wash away dirt from the outside in.
- If heavily soiled, apply a generic foaming coil cleaner and let it sit for 10 minutes before rinsing.
Done when: The metal fins on the outdoor unit are free of visible dirt and grime.
Why: Bent fins block airflow through the coils, reducing the unit's cooling capacity.
How:
- Inspect the exterior aluminum fins for flattened areas.
- Use a fin comb tool that matches the fins-per-inch (FPI) of your unit.
- Gently pull the comb through the bent sections to realign them.
Done when: All aluminum fins are straight and parallel to allow maximum airflow.
Why: Ensuring the burners ignite cleanly prevents fuel buildup and potential safety hazards.
How:
- Switch the thermostat to 'Heat' and set it 5 degrees above room temperature.
- Listen for the igniter click or see the glow.
- Observe the flames; they should be steady and blue. Yellow or flickering flames indicate a combustion issue requiring a pro.
Done when: The furnace ignites promptly and produces a steady blue flame.
Why: A cracked heat exchanger can leak deadly carbon monoxide (CO) into your home's air supply.
How:
- Use a high-lumen flashlight to look for visible cracks, heavy rust, or soot inside the furnace cabinet.
- Note: This is a visual check only; a professional uses specialized cameras for a full inspection.
Done when: A visual inspection is completed and no obvious structural damage is found.
Why: Detectors are your last line of defense against odorless, colorless CO leaks from heating systems.
How:
- Locate all CO detectors (ideally one on every floor and near sleeping areas).
- Replace old batteries with fresh alkaline or lithium batteries.
- Press the 'Test' button to ensure the alarm sounds.
Done when: All CO detectors have fresh batteries and pass the audible test.
Why: Professionals check refrigerant levels, electrical connections, and motor health that are not safe for DIY.
How:
- Book a technician in the 'off-season' (early Spring or early Fall) for better rates.
- Ensure they perform a 'multi-point inspection' including amp draw tests on motors and refrigerant pressure checks.
Done when: A certified technician has inspected the system and provided a written report.
Why: Friction in older motors causes overheating and premature failure.
How:
- Check your owner's manual to see if your blower motor or fan motor has oil ports.
- Apply 2-3 drops of SAE 20 non-detergent oil to each port.
- Note: Most modern motors are 'permanently lubricated' and do not require this.
Done when: Applicable motors are lubricated according to manufacturer specifications.