Image for blue and red swoop graphic

6 Common Heat Pump Smells Explained

By Aztil –

Image for 6 Common Heat Pump Smells Explained
  • 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 .

Request Service

What Our Clients Think Of Us


Jordan & Harold did a great job taking care of our system. Highly recommend them.
The Aztil technician Dana was very professional, knowledgeable and courteous. He resolved my issue and made the visit seamless. .
Lazaro is an excellent Tech. Courteous and Professional. If possible ask for him for all your HVAC issues.
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.
Dana was great. He was very knowledgeable. Did nice work Easy to understand. Highly recommended
Response from the owner:Hi Barry, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
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.
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.
Response from the owner:Hi David, thank you for your kind words and for being a valued customer.
Dana, my service tech did an amazing job to keep my AC up and running. He contacted me on his i, and was here in a flash.

He also updated me on the condition of the AC for the future, made some recommendations for me to consider.

Keep Dana on my service list and THANK YOU DANA!!!!
Response from the owner:Hi Jeanne, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Dana did a excellent job. He listened as to what was wrong as if he really cared. I would reccommend him to anyone. Very nice and respectable and he knew what he was doing.
Response from the owner:Hi Pat, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Niko was excellent. Very happy with his service. Explained everything and was very professional.

Yesterday no ac!! Yikes. Dana was the technician who did not leave our house until he discovered and fixed the problem. Believe me, he missed dinner and this was a Friday night. Couldn’t be happier. Dana was so professional and knowledgeable. So happy we bought from Aztil and have a service contract with them. If you ever think it’s not worth having the service contract in case of emergency, when you have no ac and it’s sweltering outside, you will be so happy you made a smart decision! Thank you Dana and Aztil.
Response from the owner:Hi E. R., 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.
Ramon was very thorough.
Response from the owner:Hi Michael, thank you for your kind words! We're so glad to hear that Ramon did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Rafael
Was very informative, polite, and to the point in explaining warranty information, and what parts was needed for my air conditioner.

I look forward yo his next visit in 6 months.
Keeps us up to date.
Response from the owner:Hi Erlene, thank you for your kind words! We're so glad to hear that Rafael did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Ramon did an excellent job in servicing my air conditioners. He also called the office to get the permit issue resolved. He informed me that Aztil was recently sold and he is enthusiastic about the new management. I also see an improvement in the communication in the past month.
Response from the owner:Hi Michael, 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 Aztil was able to provide you with such great service. We appreciate your feedback and hope to see you again soon!
The service tech Ramon did an excellent job doing maintenance on my ac and fixed my plaster on top of the ac unit!! Highly recommend!!!!
Response from the owner:Hi Chris, thank you for your kind words! We're so glad to hear that Ramon did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
I scheduled a routine check up and Cody came to my home. He was so knowledgable and found issues with AC and fixed them on the spot. He also found a major issue on my roof and I immediately called the HOA. I will definitely be asking him to come back for my next check up

Excellent Customer service Kudos Cody !!
Response from the owner:Hi Evee, thank you for your kind words! We're so glad to hear that Cody did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
I appreciate the online appointment system and the follow up communication until the Tech arrives. Dana, the technician on my job was terrific. He was very thorough and courteous, willing to answer all of my questions with clarity. The only thing that keeps me from awarding a 5 was the price. The service was very satisfying and Dana was exemplary.
Response from the owner:Hi Brett, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Cody did an excellent job. He finished in a timely manner and answered the questions I asked him.
Response from the owner:Hi Benjamin, thank you for your kind words! We're so glad to hear that Cody did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
I scheduled a routine check-up. Aztil canceled on me and the next appointment was 3 weeks later, so I was not happy about that. However, when my technician Ramon showed up, he was very thorough and efficient. He explained what he was doing and made good suggestions to maintain my AC. I was very happy with his work.
Response from the owner:Hi Elizabeth, thank you for your kind words! We're so glad to hear that Ramon did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Dana came to my house today. So impressed! He was courteous and knowledgeable. Fixed the problem quickly! Five stars!.
Response from the owner:Dear Cheryl Feldman, thank you for taking the time to share your positive experience with Dana. We're delighted to hear that he provided courteous and knowledgeable service while fixing the problem efficiently. Your satisfaction is our top priority, and we appreciate your five-star rating. If you need any further assistance, please don't hesitate to reach out.
Albert Rodriquez was through and professional. Great service
Response from the owner:Hi Susan, thank you for your kind words! We're so glad to hear that Albert did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Great job by Barreto
Response from the owner:Hi Alejandro, thank you for your kind words! We're so glad to hear that Asiel did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Michael was amazing today on our emergency air conditioning needs. He went above and beyond to accomplish getting our unit up and running!!!
Response from the owner:Hi Denise, thank you for your kind words! We're so glad to hear that Michael did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Ramon was amazing !!!! Awesome job !!!
Response from the owner:Hi Kerry, thank you for your kind words! We're so glad to hear that Ramon did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Response from the owner:Hi Doris, 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.
Ramon Serpa is the best! He performed the maintenance check on my A/C and when I told him about my husband’s allergy problems, he suggested UV lights which would improve the air quality. He installed these for me explaining the process in detail. He is the best technician we have ever had with Aztil.
Response from the owner:Hi Susan, thank you for your kind words! We're so glad to hear that Ramon did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
I've been using Aztil for over 20 years across 4 homes in Florida. From general services to complete A/C replacements, I wouldn't trust anyone else. My recent service in Port St. Lucie with Nico was excellent and he was very helpful in going over all of my HVAC system and answered a few questions I had.
I highly recommend Aztil for any HVAC issues or general maintenance.
Response from the owner:Hi Ralph, 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.
I cannot speak highly enough of our super kind technician, Randy, who came out to assess our AC today. Randy took the time to walk us through photos of the issues in our AC and offered to take care of it ASAP as he already had the parts in his truck - LOVE the preparedness! Aztil Air Conditioning is superior and we will request Randy on a go forward basis.

UPDATE 6/17/25 - Exceptional Service from True Professionals - Highly Recommend!

We recently had our ducts cleaned and sealed, plus our dryer vent serviced by Jordan and Hero from Aztil Air Conditioning, and I cannot say enough good things about their work. From the moment they arrived, these two demonstrated exactly what professional service should look like.

What impressed us most was their commitment to education - they took the time to walk both my husband and me through every step of the process, explaining not just what they were doing, but why it mattered for our home's efficiency and air quality. It's rare to find technicians who are so patient and thorough in their explanations.

Beyond their technical expertise, Jordan and Hero showed genuine respect for our home and our comfort level throughout the entire job. They worked with care and consideration, treating our space as if it were their own. As homeowners, we've all had those experiences where workers leave you feeling uneasy - this was the complete opposite. We felt completely at ease having them in our home.

Their professionalism, kindness, and attention to detail set them apart in an industry where those qualities aren't always guaranteed. If you're looking for HVAC services you can trust, don't hesitate to call Aztil Air Conditioning. Jordan and Hero will take excellent care of you and your home.

Five stars - we'll definitely be calling them for any future needs!
Response from the owner:Thank you Jessica for your positive feedback. I'm glad you were happy with the support we provided. Please keep us in mind for any HVAC needs.
Rick was terrific. Knowledgeable fast, courteous. We hope if we need a/c work, he's the one who comes out.
Response from the owner:Hi Hal, thank you for your kind words! We're so glad to hear that Rick did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Very professional, knowledgeable, and accomplished the tasks requested..Would recommend to others.
Response from the owner:Hi Judy, 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.
Jordan was excellant. Went above and beyond listening and talking me through everything.
Response from the owner:Hi Mark, thank you for your kind words! We're so glad to hear that Jordan did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Thank you Alex who diagnosed my AC issue quickly,! your superior technical skills and customer service have not gone unnoticed. Alex made my experience a pleasant one, even though my AC motor went and it needs to be ordered, the good news is it’s under warranty🤷🏼‍♂️
Response from the owner:Hi Stephen, thank you for your kind words! We're so glad to hear that Alex did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Today I had a repair/replacement done by Alex Molina
Alex is knowledgeable and explains what has to be done and it will be done
He is very polite, cleans up after himself and never complained about being in the sun for the number of hours that he had to be there to work
If anybody needs work and is lucky enough for Alex Molina to be your tech all will be done right
Thank you, Alex
Response from the owner:Hi Helen, thank you for your kind words! We're so glad to hear that Alex did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
On the ball. Courteous and efficient. Initially forgot to install cement pad, but did so when deficiency pointed out to him. Generally very pleased.
Response from the owner:Hi John, 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.
Michael King gave me outstanding service for a recent maintenance visit. He is informative, polite and above all professional. He answered all my questions and gave me good tips for ongoing maintenance.
Response from the owner:Hi Wendy, thank you for your kind words! We're so glad to hear that Michael did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Response from the owner:Hi Sharon, 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.
Good job
Response from the owner:Hi Nancy, 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.
They were excellent
Response from the owner:Hi fjoe270, 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.
Response from the owner:Hi Norman, 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.
Alez molina was excellent! Kind, proficient and efficient. Worked quickly. Am so grateful.
Response from the owner:Hi Diana, thank you for your kind words! We're so glad to hear that Alex did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Jordan & Herolson did a great job cleaning my ductwork. They arrived on time, were very nice, polite & efficient. Jordan explained everything clearly. They cleaned up thoroughly when they were done. The popcorn from my ceilings was everywhere, but they took care of it. Five stars.
Response from the owner:Hi Lisa thank you for your kind words! We're so glad to hear that Jordan and Hero did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Niko is always a competent , pleasant professional who assists me with my air conditioning units.

AZTIL responds to my calls in a timely manner.
Response from the owner:Hi Debra, 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.
Jordan an hero where effective angel. They explained evdrthing and extremely pleasant
Response from the owner:Hi Carol, thank you for your kind words! We're so glad to hear that Jordan did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Tino was friendly, professional and very helpful
Response from the owner:Hi Karen, thank you for your kind words! We're so glad to hear that Tino did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Dana was great!! Suggested a cut off switch to stop the water backup
Installed it right away
Response from the owner:Hi Mel, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Aztil is always so reliable.
Dana came today, diagnosed my A/C problem and took care of right away.
Terrific service! Thank you, Dana!
Response from the owner:Hi Susan, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Best workers, Jordan,and Hero.
Response from the owner:Hi Virginia, thank you for your kind words! We're so glad to hear that Jordan and Hero did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Thanks to Aztil AC! One of our A/C units broke down unexpectedly, and Anthony got Lazaro out to us right away the next morning. Lazaro was excellent and he found the problem with our unit very quickly. We really appreciate their quick action and professional expertise. Outstanding service from start to finish!
Response from the owner:Hi Jake, thank you for your kind words! We're so glad to hear that Anthony and Lazaro did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Just has Dana come as soon as Aztil can get there team there for our family. Dana was friendly, professional and knew his stuff.
Response from the owner:Hi Justin, thank you for your kind words! We're so glad to hear that Dana did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
The AC maintenance service was excellent. Niko Garza was professional, helpful, kind, and was instrumental in arranging for the next Senior Technician to solve the AC problem that I am having. That service will be sometime today. He also recommended the dryer vent cleaning and the in-line AC cleaning, of which I scheduled for Monday and paid today. My husband has been very ill for the past 4 years and in the hospital right now. Aztil has arranged the services, after Niko explained the situation, so that they will be completed before he comes home because a patient on oxygen and a feeding tube cannot be without power to the whole house, even a short shut down would endanger him. Thank you Niko!

Technician Rick Cochran did an excellent job replacing the AC breaker and ensuring that everything was in correct working condition. I really appreciated his kindness and professional demeanor. Thank you Rick!

Today Technician Alex Molina completed the services (dryer lint trap cleaning and inline air handler cleaning). Once again, I was fortunate to have a professional, gracious, and thoughtful person come to my house to perform the services. Thank you so much Alex!

June 2 2025 Thank you Cody! It is a relief to finally have the A/C back to what it should be. The replacement of the coil is probably what was needed a month ago. Rather than dwell on what was, I truly appreciate the replacement service and how kind you were to a grieving widow.
Response from the owner:Hi Admonis, 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.

Join The Club

Request more information by filling out the form below to learn about our Elite Cool Membership Program.

Highlights of the Elite Cool Membership Program include:

  • Members will receive priority service: Get top priority when scheduling service calls.
  • No overtime charges: We’re here for you anytime, day or night, 365 days a year, without any overtime charges.
  • A 15% member discount: Receive a 15% preferred discount on repairs not covered by the manufacturer.
  • Two maintenance calls per year: Benefit from two maintenance calls per year, spaced about six months apart.
  • AND MORE!

Need more information? Click below to call now!

Call Now

Our Partners


  • Carrier logo
  • Honywell logo
  • Mitsubishi Elctric logo
  • York logo
  • American Standard logo
  • Amana logo
  • Trane logo
  • Rheem logo
  • Ruud logo
  • Daikin logo