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


Excellent
Aztil Air Conditioning4.6
Based on 1739 reviews
David Leahy
3 hours ago
Dana explained everything. Of course it will be 80° in a week 🫡
Renae jordan
11 hours ago
Niko.
Professional and knowledgeable
Tyruz30
1 day 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.
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
3 days ago
Antonio was great. Explain everything he was doing. Unfortunately I cannot afford the price of a new unit.
John Mancini
3 days ago
Diane Steeley
3 days ago
Alex Molina was very professional, polite and respectful of my space. He kept me updated on what was happening throughout the whole process. Would definitely use again and would highly recommend!
Holly Henkel
4 days ago
Great, friendly, quick service. Took care of problem and I paid extra for emergency service. Had first used AC coolair thru my home warranty and took 2 day reply and lied that he couldn’t fix it!
Cheryl Abrams
2 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
2 weeks ago
Aztil was wonderful my motor went and Dana came and replaced it incredibly fast Thank You Dana
Deborah Foley
2 weeks ago
I asked for Michael King because he is a very Good Service Man and I’ve had him do my 6 Mo check up before. He brought Dana Dussslt with him and I now had two very professional service men. What a good day!
Renee Krul
2 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
2 weeks ago
Our technician, Lazaro Powery was congenial, knowledgeable, and explained the procedure very well. We would recommend him to others.
Ramon was courteous and professional. Took the time to explain everything. I’ll request him for service in the future.
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
3 weeks ago
Ramon was knowledgeable, friendly and highly competent!
Donna Astrab
3 weeks ago
Serviceman Dana Dussalt was excellent, courteous and outstanding.
A S
3 weeks ago
Niko was terrific as always!!
Gisele Iarrera
3 weeks ago
We recently had a maintenance call. The next day the air conditioner stopped working. Our second technician was Dana Dusseault and we had an excellent service. He found the problem right away. He had a trick to find the water drainage ( which had been buried) We would highly recommend.
Arlyne Gitomer
4 weeks ago
Sabrina Ferreira
4 weeks ago
Michael did a great job! Thanks.
Linds Swn
4 weeks 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
Leah Rigot
4 weeks ago
ANTONIO was reference as a Sr. Tech by Office Staff. When He arrived at my home he was immediately very professional and demonstrated that he was competent to do the heater replacement. I would request Antonio to do future service calls.
Response from the owner:Hi Leah, 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.
joseph gonzalez
4 weeks ago
Excellent. Albert Rod. I excellent.
Mitzi Moore
4 weeks ago
Juan Ortega was sent to my home to remedy my AC problem. He diagnosed the problem after about 10 minutes of testing and had it repaired shortly thereafter. He was professional, kind & compassionate. Thanks Juan!
June
4 weeks ago
Ramon is very kind and very knowledgeable!! He always shares information and always answers all of my questions. Thank you Ramon!!
Joy Ashkenas
1 month ago
Jordan and Jalen performed the aeroseal and Juan did an excellent job
Susan Edenzon
1 month ago
Jorge Rivera was the technician that installed our new air conditioner unit. He was promo courteous, and did an excellent job installing our unit.
CIHRHH H.
1 month ago
Rafael and Asiel installed my new A/C today. They were super. Everything went as planned. I am a happy camper.

12/5/25 Alex came for tuneup and fixed thermostat problem. Wonderful experience. 5 stars.

12.29.25 Alex came to fix a/c thermostat wiring problem. A/C did not put out heat. He fixed within 5 minutes. 5 stars.
Response from the owner:Hi Cihrhh, thank you for your kind words! We're so glad to hear that Rafael and Asiel did an excellent job and that you were pleased with the outcome. Thank you for being a valued customer.
Ken Laffer
1 month ago
Paul is an amazing tech he came on time completed the project and my house is cool again. I have been with Aztil for 18 years and only have good things to say and Paul is amazing.
Mr. King was amazing. Professional, clean and courteous.
Regina Smit-Sio
1 month ago
Antonio Moreno is Excellent! Professional, courteous and caring.
Michael King was an EXCELLENT service technician. He was very polite and was able to pinpoint the problem. He was not trying to pressure us to get anything done other than the issues we were having. We have been with Aztil for over 20 years servicing both of our homes and having Michael as our technician by far has been the best experience.
Liz hunt
1 month ago
Aztil always comes through even at the last minute. Their technicians are very knowledgeable and respectful and even took out my old filter to the dumpster!! Thank you
cathy lazaroff
1 month ago
Elder was terrific. Knowledgeable and efficient
A pleasure to work with
Joseph Rizza
1 month ago
Jordan Jalen were here and I was impressed by their performance and professional attitude. Thank you and have a great Holiday🎄
Elizabeth Sugar
2 months ago
Niko was extremely helpful solving our emergency…The capacitor stoped working!!
Elizabeth Ness
2 months ago
Very good. Lazaro was courteous and professional.
Richard Grossman
2 months ago
Dana is a great Technician. He is very knowledgeable and personable in addition to being extremely thorough. He did my A/C check up and kept me informed as he proceeded through the process. Very pleased with Aztil and have always been very happy with their technicians and sercvice.
Response from the owner:

Dear Richard Grossman,

Thank you for your glowing review! We're so glad to hear that you had such an excellent experience with Lazarro and Antonio. We pride ourselves on providing top-notch service and are thrilled that you have chosen to sign a 5 year contract with us. We look forward to continuing to provide you with the best service possible.

Thank you again for your kind words.

Sincerely,
AZTIL
Yves Carpentier
2 months ago
The gentlemen that came to replace my air conditioner were very friendly and pleasant. I was pleasantly surprised at the speed and efficiency at which they worked. Jorge Rivera did a great job and I will commend Aztil Air to everyone. Thank you.
Dana was great on time very professional
Cheryl Cannizzaro
2 months ago
Paul is friendly and kmowledgable
Response from the owner:Hello Cheryl. Thank you for your feedback. We appreciate your business.
Steve
2 months ago
Our AC just crapped out on a Sunday morning. We called and Dana was in contact with us immediately. He called, we gave him a brief run down of the issue. He arrived promptly, was professional, found the issue, fixed it, tested the system and had us back up and running in about an hour. He also
let us know our service contract was expiring in a couple of months so we renewed it on the spot. We HIGHLY recommend them for your AC needs.
Chris
2 months ago
The service tech Cody did an excellent job doing the maintenance!! Very friendly and courteous, 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.
Saguee Saraf
2 months ago
Technician Michael King was very thorough and friendly. He spent hours painstakingly explaining and figuring out why my air conditioning and heating unit wasn’t working until he solved the mystery.
Joel Sternin
2 months ago
Niko was pleasant, capable and informative. I’m greatful to have in service my AC unit.
Dan Keane
2 months ago
Antonio was great, here on time and provided 6 month service- we renewed our contract for another year. A dollar a day is a great deal!!

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