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6 Common Heat Pump Smells Explained

By Aztil –

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  • It is not normal for a home to have weird smells, especially when it has air conditioning and heating. An offensive odor that you can smell throughout the house is a sign of trouble. The good news is that these odors are quite distinctive, and so the cause behind them is relatively easy to identify. Usually, most odors will have a link with one heat pump problem or the other. The sooner you identify them and take corrective action, the lesser the chances of any disruption in your comfort. To make things easy for our clients and readers, here is a list of standard heat pump smells and their causes explained.

    Six Common Heat Pump Smells Explained

    1. Musty Or Stale Odor – When you enter a home or building that has been closed for a long time, the indoor air smells off. The best way to describe it is like that of stuffy and old air or the smell of dirty socks. The reason for this smell is mold and mildew that grow in the damp areas of the home. The most conducive environment for their growth and propagation is found in the heat pump near the evaporator coils. From here, the smell is picked up by the circulating air and dispersed throughout the house, making it stinky. 

     How To Get Rid Of It – Staying on top of the annual maintenance routine is the best way to remove the musty odor. During maintenance, the inside of the heat pump is cleaned thoroughly, which removes all mold and fungus. Once they are clean, there is no reason for the stale smell.

    2. Rotten Fish Smell – The smell of rotten fish is hard to ignore. It is so repulsive that staying indoors becomes an ordeal. Your heat pump will emanate this strong and vile odor when some component (plastic or metallic) starts overheating. Before doing anything else, switch off the heat pump to prevent further damage to the unit. Some of the reasons behind the smell could be:

    1. Problems with heat pump wiring.
    2. Overheating of plastic components or melting of rubber coating.
    3. Mechanical issues.
    4. An overheating motor.

    How To Get Rid Of It – Getting rid of the rotten fish smell is a matter of expert handling. You need an HVAC technician to eliminate this heat pump smell as it involves opening the heat pump and checking its internal parts.

    3. Rotten Egg Smells – Rotten egg smell is like the smell of sulfur. Such a smell comes from the heat pump if there is a dead animal or critter inside the ducts. Often, small animals find their way inside the ducts for warmth and protection and die inside. As their body starts rotting, it releases the offensive smell of decomposition. 

     How To Get Rid Of It – To get rid of the rotten egg smell, call your local HVAC technician. He will clean the heat pump and the ducts, if necessary. Once the body of the dead critter is removed, the smell goes away on its own.

    4. Burning Rubber Or Plastic Smell – If it smells like something is burning, it most probably is. Never ignore such smells. Often an electrical problem inside the heat pump will result in wires burning. Essentially, it is the rubber tube on the wires and the surrounding plastic that starts burning. If you fail to recognize this type of odor, the chances are your heat pump will develop a serious issue and stop working altogether. The other probability, if you are lucky, is that the circuit breaker will trip to prevent further damage.

    How To Get Rid Of It – Only an HVAC technician can help you tackle this problem. He will have to open the heat pump to determine where the electrical problem exists and take remedial action.

    5. Heat Pump Smells Like Sewer – If your heat pump produces a sewer-like smell, do remember, there is a high possibility that the circulating air has picked up the smell from elsewhere. The odor does not always initiate in the heat pump. A sewer-like smell means that somewhere in the house, the sewer line is backed up or broken.

    How To Get Rid Of It – You can eliminate the sewer smell only by clearing the backed-up line or fixing the broken pipe. However, this task can only be completed by the company that deals with sewer lines in your locality.

    6. Burning Dust Smell – A heat pump, like any other heating and cooling system, accumulates dust. Switching it on after a long interval results in a strong burning odor that typically goes away on its own within 5 or 10 minutes.

    How To Get Rid Of It – One way of ensuring that this type of odor does not come at all is by ensuring timely maintenance of the heat pump. If, for some reason, that’s not possible, at least clean the unit thoroughly. Else, allow the unit to run for, say, 10 to 15 minutes, and that should be enough time for the odor to go away. If not, call your trusted HVAC technician.

    Takeaway

    The heat pump is not designed to produce any smells. These are actually indicators of what is happening within the heating and cooling system. Hence, it is necessary to be a little vigilant. Thankfully, most heat pump smells are not a thing of grave concern. Yes, they are disgusting and repulsive and make staying indoors an ordeal, but they don’t spell trouble for the system. The same cannot be said for the burning smells. Our only advice is to let your HVAC technician know of the odors as soon as they originate. They shall take care of the rest.

    Aztil Air Conditioningcan help the residents of South Florida find the reason behind their heat pump smells. Our trained, certified, and experienced technicians will thereafter undertake corrective measures to remove them, so you no longer have to suffer unnecessarily. You can also engage our services for HVAC installations , repairs, and maintenance. We also provide 24/7 emergency services . To book an appointment, call +561-559-2205 .

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Theodora Hansen
4 hours ago
Elder wonderfully job.
Irene Scavelli
12 hours ago
We had a great servicing experience today with Paul the technician. He has serviced us in the past and is always professional, informative, helpful with suggestions on proper repairs to maintain our system in good functioning order.
Larry Scavelli
12 hours ago
Paul G is a pro ! Polite and efficient!
Les Matthews
19 hours ago
Lazaro is an excellent Tech. Courteous and Professional. If possible ask for him for all your HVAC issues. Also just had a total replacement of my AC unit by Angel and Hero . They did an excellent job in and out in 2.5hrs would recommend these install professionals.
Response from the owner:Hi Les, thank you for your kind words! We're so glad to hear that Lazaro did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Ryan del Rosario
20 hours ago
I had Alex and Skyler from Aztil out for an air duct cleaning today, and they did a fantastic job. They were professional, efficient, and finished the work fairly quickly.

Beyond the cleaning, I was especially impressed with their troubleshooting. We had an inspection the previous day (a different tech) where the AC breaker was accidentally left off. When I mentioned the AC wasn't acting right, Alex didn't hesitate to look into it and identified the issue immediately. Truly appreciate the extra effort and the great service!
Tim Bresnahan
3 days ago
Yvonne Cacioli
3 days ago
Elder Zavala was my technician today to replace a bad sensor in my unit. He is very kind and very knowledgeable. I had a great experience with him.
Response from the owner:Hi Yvonne, thank you for your kind words! We're so glad to hear that Niko did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Gary Ackendorf
3 days ago
Skyler was a very nice young man and completed the work very well. Seems a great asset for Aztil
Rose Callahan
3 days ago
Elder
Andrew Beck
3 days ago
Elder was great, explained my options clearly following routine maintenance.
Deborah Foley
3 days ago
Naraldo was professional & efficient in his ability. I would rate him a 4.5 in the quality of work on installing a tankless water heater.
I did feel like the price was too high
Home Depot has the tankless heaters for $500. 1500.00 for installation was a bit high, but when you need hot water you pay it or go without.
Niko

Excellent
David Eisman
4 days ago
Aztil was good but Dana D was who helped this be better. He arrived when he promised. He was professional, knowledgeable, & efficient as well as informative. I will ask for him anytime I need my AC serviced. Excellent job.
NIKO GARCIA is professional, neat, courteous, and friendly! He did a great job
Response from the owner:Hi Laura, thank you for your kind words! We're so glad to hear that Antonio and cody did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Steven Smith
4 days ago
Amazing company! High quality workmanship and friendly people who really seem to care.
Paul Volkert
4 days ago
Great and smooth maintenance
Harvey Samuels
6 days ago
Niko & Juan were excellent on the periodic service diagnosis. Dana again did excellent install of the the subsequent dryer replacement.
Tatore Man
7 days ago
Lazaro was great, he explained the repair needed in detail, and was very helpful in explaining the maintenance needs for the unit. I will always ask for Lazaro , for my future needs from Aztil
joel kaye
7 days ago
Paul G is great. He is one of the few who explains everything before work is started and reviews total job with pictures when done.
Joel Kramer
1 week ago
Antonio Moreno is a professional qualified HVAC technician. He solved my issue.
Response from the owner:Hi Joel, thank you for your kind words! We're so glad to hear that Aztil did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Mario M
1 week ago
Reliable service from Lazaro.
Mary Anderson
1 week ago
Niko and Juan
Travis L
1 week ago
Steven and the team are amazing!
This is coming in late since I didn't know this review was on the phone until I pushed the screen and this popped up. Great job from Albert R. On the drain pump cleaner instalation. BZ [well done].
Alex Sibilia
1 week ago
Michael was an awesome tech.. Very knowledgeable and friendly.. Will request him again..
Miguel Valera
1 week ago
Renae jordan
2 weeks ago
Niko.
Professional and knowledgeable
Tyruz30
2 weeks ago
Great experience with Antonio, we are very appreciative of his service and helpful attitude. He did a very good job and was informative. We appreciate Aztil and Antonio for all their assistance.
Wendy Phillips
2 weeks ago
Jorge and Dave we’re extremely professional. The AC installation was done quickly and meticulously. I can’t recommend them enough!

I also want to give a shout out to Paul Gross. He was my initial contact with Aztil. He explained all my options to me and suggested the best unit for my home. Paul was able to get me a great price and I’m very grateful for his advice.

UPDATE: Six months after the installation my HVAC unit stopped working. Of course it was a Sunday and the coldest day in 10 years! Michael was dispatched and he immediately identified the problem. He purchased a new circuit breaker and installed it quickly. Michael was extremely professional. Aztil is fortunate to have a technician as skilled as Mike.
Response from the owner:Hi Wendy, thank you for your kind words! We're so glad to hear that Jorge and Paul did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
daniel watson
2 weeks ago
Antonio was great. Explain everything he was doing. Unfortunately I cannot afford the price of a new unit.
John Mancini
2 weeks ago
Cheryl Abrams
3 weeks ago
Michael was Excellent, extremely Personable, and did a very thorough cleaning and updating of my air conditioner. He was a pleasure to deal with.
What a lovely and efficient young man!!
Everyone should request him in the future.!

Cheryl Abrams Shaller
Response from the owner:Thank you so much for the wonderful review, Cheryl Abrams! We are so glad that Ricardo was able to exceed your expectations and that you would recommend AZTIL. We always strive to provide excellent service to our customers.
Cathy Cannella
3 weeks ago
Aztil was wonderful my motor went and Dana came and replaced it incredibly fast Thank You Dana
Renee Krul
3 weeks ago
Jorge is very professional and knowledgeable. He answered any questions I had about the new system and any concerns I had. He worked efficiently and systematically with his associate. At the end, the place was spotless that you would not know he was working here.
Glenna Pocceschi
3 weeks ago
Our technician, Lazaro Powery was congenial, knowledgeable, and explained the procedure very well. We would recommend him to others.
Lynn
3 weeks ago
2026-***UPDATE***
Once again, Dana Dussault delivered outstanding service. Professional, knowledgeable, and honest, with a clear commitment to doing the job right. It’s a pleasure working with someone who consistently brings integrity to their work.

Thank you, Dana!!!!

Dana Dussault is awesome.

After 4 hellish days without A/C, he came to our rescue. My family and I thank you for your swiftness and professionalism.

God bless you
Response from the owner:Hi Germaine,

Thank you so much for your wonderful review! We're glad to hear that you had an excellent experience with our service. We pride ourselves on our knowledgeable staff, and it's great to know that Dana was able to provide you with such great service. We appreciate your feedback and hope to see you again soon!
Elaine Collins
4 weeks ago
Ramon was knowledgeable, friendly and highly competent!
Lisa Nocenti
1 month ago
Niko was great. Highly recommend him.
Sue Lightner
1 month ago
I think it is indicative of the heart of a company when every person from that company who comes to work in your house and on your system is knowledgable, personable and treats your home with care. Aztil, what great people you have! Paul, Jorge, Dave, Jordan and Jalen, thanks for a terrific experience installing our new system, and cleaning and sealing our ducts. You all were so kind, knowledgable and careful!!
donald willett
1 month ago
Cody was great! Very knowledgeable and friendly and went out of his way to complete a task today that some may not have
maria Pacheco
1 month ago
The Aztil is an Excellent Air Conditioning company Alex Molina
⭐️⭐️⭐️⭐️⭐️
Response from the owner:Hi Maria, thank you for your kind words! We're so glad to hear that Aztil did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Sonia Padget
1 month ago
Arlyne Gitomer
1 month ago
Sabrina Ferreira
1 month ago
Michael did a great job! Thanks.
Linds Swn
1 month ago
Thanks to Nico who did a great job today with our maintenance plan. When we had a repair issue in the past, Cody also did a great job helping us and also assisted us with our FPL surge claim

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