musty odor from central ac system

Paul_69

how should a ac professional approach a call where customer says they have musty odor coming out of ac vents. i am a contractor and i have not had much experience at all with this type of complaint.is it the duct work ? is it a mold/ mildew issue? it certainly out of the ordinary call for me. i thought about maybe it is a evaporator being mildewy or even the duct work. i just dont want to be wacking away at something that i may not be able to cure. do they need a remediation company to evaluate?i have read other articles where evaporator is leaned but it didnt go away etc.it is a residential home with some age on the unit. i could check drainage and clean coil but if it doesnt solve it they are going to come back to me. i thought a duct cleaning would be a good start.i have only heard this compliant 2-3 times in my 8 years in contracting. i am use to mechanical issues but not this odor situation.any advice would be appreciated for future skills in thi matter......thx

RJ_4

smell

Start at the evap coil, make sure the drain pan is clean, check that the drain is clean and everything is pitched and piped correctly (make sure there is a trap if needed )  there are products available for cleaning and treating pans.   I would start there

BillW

musty AC smell

Absolutely check your condensate pan and drain to make sure they are pitched properly and draining.  You may also have an algae growing on your cooing coil, and if so, you will need to clean it, a job best left to the pro's, but if you can do it yourself, use "Simple Green", which cleans well, smells good and is non-toxic and non-corrosive.  Rinse well.  Once cleaned, the coil should be OK if the pan is clear, drains properly, and you maintain your filtration on a regular basis.  Another possibility is that there may be a water leak somewhere in your duct work.  Look for rusty or white discoloration on the duct, and fix it asap.