The Fix-It Playbook — Indoor Evaporator Coil Flowchart | Free 1-Page PDF | 2026 Edition

AC air weak or musty? The indoor coil may need cleaning — or it may not be yours to clean.

Two questions sort it. Have you changed the air filter recently — a dirty filter is the number-one cause of a dirty coil. Then pull the access panel: a reachable coil with light dust is a DIY clean; sealed, matted or moldy is a pro job, and the sheet says why.

The sheet also carries a DIY vs pro quick check, and a plain line on when to stop and call a pro.

One page. Print it or keep it on your phone. Free instant PDF download, yours to keep.

If the tree sends you deeper: How to Clean Your Indoor Evaporator Coil ($6) adds the complete reachability checklist, the full foam-cleaning step-by-step, and how the coil ties into your filter and condensate drain. All five heating and cooling guides come together as the HVAC Maintenance Kit ($14), and all 24 year-round guides are in the Core Library ($49).