What causes a mold smell when I turn my HVAC unit on

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Derek Cole is the General Manager of One Hour Heating & Air Conditioning®, an independently owned and operated franchise based in Laurinburg, North Carolina since 1953. He has more than 17 years of experience in the HVAC industry and has created two You Tube broadcasts, The Comfort Experts and #AskDerekCole, filled with tips and tricks on saving energy and being comfortable. He was named the Top 40 under 40 in the HVAC industry by the News magazine and featured in Entrepreneur Magazine Franchise Player Spotlight. Derek has also been seen on CBS, FOX, NBC, ABC, and Bloomberg Business sharing about One Hour Heating & Air Conditioning®.

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[scotts.]

I have this issue and UV lights alone wont fix the smell but just reduce it since the loops at the ends of the condenser are covered up. I even have UV lights below and above my condenser.

[davidsandoval]

Just watched your video we installed an air scrubber but still getting a musty stong smell in closet would you know we're to look next thanks

[chronicpainwarrior]

Installed a UVC light and still have the dirty sock syndrome...My research shows it's a 'common' problem with heat pumps and that 'pros' should know better than to install these units in non-climate controlled areas of the home. Mine sits in the attic space, which is not conditioned. This has allowed the various stinky spores to grow on the coils and elsewhere. I paid to have a new plenum custom built and installed. Guess what? It didn't fix the problem. I get the same old song and dance from my HVAC pros... "we could "try" this, or "try" that... " I've told them I don't have the money for their "theories". Anyway, I'm pretty sure they already know the problem is chronic for heat pumps because of where they get installed and there aren't really any good fixes other than to live with it. But they still try to sell you something. I ordered some kind of cleaner another guy recommended today so we'll see if it was a waste of money or not. SMH

[mikerawley]

Please lose the irritating "music"

[mssburr]

what causes a brand new ac both outside unit and indoor coil to have a mildew smell...
The unit was installed about 4 weeks to the end 2020 summer...

I just turn it on today because it was unusually hot for the winter..
And a bad order was coming out.
All the filters are new...
There is no smell at the inside unit...
And there was no smell they last time the unit was used...

I turned it right off.. Because it stunk.

[cherylthec]

Help please...I have a brand new Lennox hvac system...and now have this odor that is getting stronger and stronger for the last 6 months...installer fh furr says they dont smell anything and I'm I also have the uv light installed and they cleaned the ducks... please... the odor is making me sick...

[ange]

Is it weird that I like the musty smell of air conditioning?