AC emitting foul smell

[EHH]

My carrier split AC is emitting foul smell like some kinda rotten old stuff.
Got AC serviced last week for summer season. It started giving foul smell the next day. Indoor unit was re-serviced with soap water etc. After re-servicing AC was not used till today. In other words the smell never went away after re-servicing.
AC was working fine before winters. There was never any problem of smell etc ever till then. This is the first time the problem has emerged.
AC is 7 years old inverter model. Service was done by the brand.

What is the solution ?

 

[chyawanprash]

Sounds like mold/mildew. Very hard to clean, esp if it's a 5-star model. Try those sprays meant specifically for killing mold. Car servicing guys use it a lot.

 

[blr_p]

Where is mould though. If it's in the internal unit then it will have to be disassembled and cleaned.

Must be operating in a high humidity environment for this problem to happen

 

[Afxal]

Had the same issue.

Please check if the pipe on the outside is oozing water or not, maybe the hole in the inside unit for getting the water out is clogged.
If it is not clogged, then just let the AC run for long hours continuously, the smell will go away.

If the pipe is dry, then the hole is clogged, and you will have to get it cleaned. Though, there is a trick to just blow heavily from the outer pipe so that the hole inside gets unclogged but better leave it to the technician if you don't know what you are dealing with.

 

[Slayer88]

I had the same issue.. mine was a window AC. My doubts that a rat died in there. But the smell went away in a few days..so yea.. run it for a day or two, perhaps in fan mode and see if it fixes itself.

 

[EHH]

Sounds like mold/mildew. Very hard to clean, esp if it's a 5-star model. Try those sprays meant specifically for killing mold. Car servicing guys use it a lot.

You mean something line this product says no need to wipe (I guess no need to wash with water). It's a 4 star inverter.

Where is mould though. If it's in the internal unit then it will have to be disassembled and cleaned.

Must be operating in a high humidity environment for this problem to happen

Service guys said outer unit doesn't have any role in smell, only inner unit does that.
Location NCR. Unit was working perfectly before winters. 6m of non-operation is common during winters. There was no such problem ever before and other ACs are working OK.
Will pipe wash the outer in eve anyways.

Had the same issue.

Please check if the pipe on the outside is oozing water or not, maybe the hole in the inside unit for getting the water out is clogged.
If it is not clogged, then just let the AC run for long hours continuously, the smell will go away.

If the pipe is dry, then the hole is clogged, and you will have to get it cleaned. Though, there is a trick to just blow heavily from the outer pipe so that the hole inside gets unclogged but better leave it to the technician if you don't know what you are dealing with.

Outlet pipe is dispensing water as it should.
Also if its clogged, indoor will leak.
Outlet usually gets clogged in month of August from my experience, link.

I had the same issue.. mine was a window AC. My doubts that a rat died in there. But the smell went away in a few days..so yea.. run it for a day or two, perhaps in fan mode and see if it fixes itself.

Running now. Lets see.

 

[manohar5321]

I had an old window unit not being used often smelling like that . kept it running for a couple of days about 5 hours daily and smell went away on its own.

 

[chyawanprash]

You mean something line this product says no need to wipe (I guess no need to wash with water). It's a 4 star inverter.

Get it from a reputed brand which explicitly mentions mold. Something like this: https://www.amazon.in/dp/B01LZ76HXG. No name brands usually have acids which can corrode the fins.

Humidity is low these days. So, running the AC at low temperature will get rid of the smell in a few days. It won't kill the mold though.

All inverter ACs have some sort of blow-dry mode (different from dehumidify mode), where the compressor stops and the blower runs at high speed to get rid of the moisture from the evaporator. This mode usually kicks off automatically whenever you switch off the AC. This prevents mold overgrowth over time. Do this process manually if your AC doesn't have this function. Run AC for 10 minutes in high fan-only mode before switching it off.

 

[nRiTeCh]

I have faced this issue esp. when AC was not in use for a good 4-5 months. It functions properly aka cooling was uncompromised but in between it used to emit some mild rotten or fungal odor.
I observed that in Auto mode it used to emit such foul odor. I then started to set custom temp with custom fan blow speeds, this didn't exactly get us rid of the odor but was better manageable at least 70%. The odor only used to get emitted either when we turned on the AC/during initial cooling or in middle of night. Total combined count was roughly 40mins or so and this then wasn't a regular affair as well.
I again tried auto mode for testing, and it again started giving out frequent bad odor.