Ductwork maintenance checklist
Updated August 2026
Keeping ductwork tight comes down to sealing accessible joints with mastic once, wiping the registers each season, and a full professional cleaning only every 5 to 8 years if the system runs dusty. The U.S. Department of Energy pegs leakage in a typical duct system at 20–30% of the air the blower moves, so the sealing is where the money is. Everything but the hidden runs and a deep cleaning is DIY.
| Task | Interval | Effort |
|---|---|---|
| Wipe and vacuum supply and return registers | Seasonal | 10 min · DIY |
| Feel accessible joints for escaping air while running | Seasonal | 10 min · DIY |
| Confirm no register is closed or blocked by furniture | Seasonal | 5 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Seal reachable attic or crawlspace joints with mastic | Once (recheck 3–5 yr) | $20–40 · DIY |
| Confirm boots are sealed where ducts meet walls and ceilings | 3–5 years | 15 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Inspect exposed runs for crushed sections, gaps, or loose straps | 3–5 years | 30 min · DIY |
| Verify flex duct is supported, not sagging or kinked | 3–5 years | 20 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Have ducts professionally cleaned | 5–8 years | $300–700 pro |
| Ask a pro to pressure-test and seal hidden leaks | As needed | $500–1,500 pro |
What neglect costs
Leaky ducts are a slow, invisible tax. When 20–30% of conditioned air escapes into an attic or crawlspace, the furnace and AC run longer to hit the same temperature, which shows up as roughly $300–600 a year of wasted energy in an average home. Dusty return leaks also pull insulation fibers and attic grime into the air you breathe. A $20 tub of mastic and an afternoon closes most of the gap; a proper seal keeps the system delivering what you pay for and helps the ducts reach their full service life.
Leave these to a pro
Hire out anything past arm's reach. A professional duct cleaning runs $300–700 for a typical home and earns its keep only every 5 to 8 years, or after a remodel, rodents, or visible mold. Sealing leaks buried inside walls and ceilings is a job for an aerosol-sealant service (often $500–1,500), since a brush cannot reach those joints. If airflow feels uneven room to room, a tech can measure static pressure and balance the dampers, which pairs naturally with your AC tune-up or furnace service.
This whole checklist ships as reminders in OnOtto: every task above, on the right schedule for your home, snooze-proof.
Load this checklist as remindersFrequently asked questions
Does duct cleaning actually lower my bills?
Rarely on its own. Cleaning removes dust and debris, which helps air quality and keeps the indoor coil cleaner, but the EPA has never shown it cuts energy use in a typical home. Sealing is the money job: closing 20–30% leakage saves far more than a $300–700 cleaning ever will. Clean the ducts every 5 to 8 years for air quality, and reserve it for real triggers like mold, a rodent nest, or a post-renovation dust load.
How can I tell if my ducts are leaking?
Look for rooms that never reach the set temperature, high bills with a system that runs constantly, and dust streaks around register edges. In the attic or crawlspace, run the system and feel along the joints and seams for escaping air. Old cloth duct tape that has dried and peeled is a giveaway. You can confirm the whole system with a professional pressure test, but reachable leaks are usually obvious the moment you look.
Can I seal ducts myself, and with what?
Yes, for anything you can reach. Use duct mastic, a paint-on sealant, or a foil-backed tape rated UL 181, never cloth duct tape, which dries out and falls off within a couple of years. Brush the mastic over every joint, seam, and boot connection, then let it cure. A tub costs about $15–25 and seals a whole accessible system. The runs hidden inside walls need a professional aerosol sealant instead.
How often should ducts be inspected?
Give exposed runs a quick look every 3 to 5 years, or whenever you are already up in the attic or crawlspace. You are checking for crushed flex duct, disconnected sections, sagging straps, and loose boots. Catching a fully disconnected run matters: it can dump an entire room's air into the attic and spike a bill overnight. A full professional inspection pairs well with a duct cleaning every 5 to 8 years.