Said It Here

AC compressor making weird sounds after servicing

Using coil spray and water to clean an outdoor unit can leave the compressor making strange buzzing sounds, particularly when temperatures climb above 85 degrees. This leaves homeowners anxious and unsure whether the post-maintenance noise is something they should actually worry about.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Turning off the unit
  2. 2
    Calling an HVAC technician
  3. 3
    Checking if the condenser coil is dirty
  4. 4
    Comparing the sound to other units heard in the neighborhood

In their words

Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.

r/hvacadvice2 people · September 2026

“Someone help! I serviced my AC unit and now the compressor is making weird sounds.”source ↗

“Yes I removed the power before servicing. I used coil spray and water.”source ↗

plencoolilikeplen · r/hvacadvice · 7 upvotes

“noticed the new compressor starts making a buzzing sound, but only when outdoor temps are above ~85f. This is driving my OCD crazy.”source ↗

“is this something I should be worried about?”source ↗

ljbrandt500 · r/hvacadvice · 1 upvotes

Where this came up

People with this problem also raised