January 7, 2008


Occasionally people smell mysterious fish odors in their homes. Often such problems go undiagnosed for several weeks or months before the source of the odor is uncovered. People who are trying to be helpful may suggest that these smells are from dead fish in the yard, or dead rodents in the walls, others may suggest they are the result of sewer gas backing out of your plumbing system, or mold odors resulting from wet building materials. Being a former health inspector, and a current mold inspector and indoor air quality consultant I know that

mold, rodents, and sewer gas do not smell like rotten fish at all. Being lead down the wrong path can be disastrous if the source of fish odor in your home is actually from plastic electrical components heating up in your walls. The following is the summary page from an inspection that was conducted on 7-30-07 at a trailer home in Barefoot Bay Florida North of Vero Beach Florida. Fish odor in the property was from an overheating electrical component. Though the component was only at 130F and not likely to catch fire anytime soon, such conditions should be addressed by a licenses electrical as soon as possible.   The client complained of a odor that comes and goes, the odor appeared to be centered near water damage and decay in the trailer wall of the front bedroom. This damage was investigated and was found to not be producing fish smells, nor excessive mold odors. The client reported that this mystery odor comes and goes and in fact the inspector observed the odor to be very weak at the start of the investigation and it changed in strength a few times. Though odors coming and going sounds strange, but it is common and easily explained. When the sun heats a wall the air in that wall expands and pushes air and any unusual odors that may be present out of the wall, and when the wind blows it creates pressure differentials in the wall that also may force odors out of the wall, in addition an AC unit turning on can pull air out of the wall via it’s AC return. When the inspector smelled around the breaker panel in this room the inspector smelled a mild to strong odor that seemed exactly like dead fish. The client reported that the odor filled the entire room in the past and appeared stronger when the AC unit was turned on.

The inspector inspected around the breaker panel and found the odors to be strongest near the breaker panel.

The breaker panel is a typical 150 Amp breaker panel with copper 120 volt wires and breaded aluminum main service cables and some braided aluminum 240 volt wires with antioxidant paste was observed. No rust, or burnt wires, or other unusual conditions were noted in or around the panel.

When the inspector removed the breaker panel cover the strong fish odor rose out of the panel and upward along with warm air rising from behind the panel. Warm air rising out of a panel is not typical. The identity of the compound creating this odor is unknown but it may be the result of the breakdown of some man made plastic like substance in the breaker panel that is breaking down because of the heat.

Some of the breakers are warmer than normal thus the breakers are overheating and causing the panel to be warm. The hottest breaker was the dining room breaker at 130F this breaker appeared to be the source of heat when tested with a laser thermometer.

This condition should be checked by an electrician as soon as possible. This may indicate loose connections in the panel. Warning overheating electrical components can cause house fire. If the odor is not originating in the panel it may be originating from deeper in the plastic conduit that brings the wires to your panel. Have any and all required repairs made soon. The client was warned during the inspection that she should contact an electrician because of the overheating breaker that may be a fire hazard and contact him because of the odor it produces. The client reported to this inspector repeatedly that she would have her electrician check the condition the next day.Additional sampling for volatile organic compounds will probably help this inspector identify the fumes you are breathing such can be done if desired, but getting this condition repaired by an electrician is more important than identification. You may need to have an electrician change the overheating dining room breaker or the entire panel, have this condition corrected properly and soon for safety.

The following is some information that the inspector found on the Internet regarding this condition. It confirms the inspectors findings that overheating electrical components can cause fish odors in homes.

Hello all – My parents are having an issue with a somewhat fishy odor that comes & goes in one area of the house.

We kept smelling a fishy smell and it turned out to be an electrical outlet that was melting inside the wall. The circuit was overloaded (we did not know that). It took the outlet smoking before we figured it out. Since then we smelled that fishy smell again and found another outlet to replace.

  • Posted by logic (My Page ) on

    Mon, Jul 17, 06 at 16:39

    On another thread, a “fishy” smell turned out to be melting plastic light covers….the bulbs were too high wattage. I would check everything plastic in the area.

    • Posted by gaffari (My Page ) on

      Tue, Sept 26, 06 at 13:30

      Found the source of the smell. Thanks to the posting by LOGIC – I saw that the plastic fixtures (supplied by the builder) were melting. We took them down and they smelled like fish!!!! Thanks for the all the help.


    My apartment has a constant smell of fish in the kitchen but despite cleaning it with every product known to mankind the smell won’t go away.

    This can be an electrical problem. I had an undeniable fish smell in my house. Apparently some wiring (especially in old homes) will give off this smell when it overheats- check your lights and other electrical devices. or better yet call an electrician.

    A few weeks back, I wrote into AAC about a fishy odor that was coming from my dining room. This wasn’t a constant smell.

    Well we finally found out what the smell was. One night, around midnight, I was going to bed and turned off the light in the dining room. I could smell that fishy odor again, this time it was not as strong, but I could smell it.

    I went over to the dining room window where the smell was much stronger. I kept smelling around the window until I came to an electrical outlet. As I got closer to the electrical outlet the smell was stronger. I touched the outlet and it was extremely hot. The smell was coming out of the holes.

    We are very fortunate to have had this warning (smell) as you hear families perish from faulty wiring or electrical fires.

    We discovered the smell in my daughter’s room!It is coming from the ceiling light. We were burning a 100W bulb in a max 75W socket and we think it was making the socket smell (must have been plastic getting too hot). Anyway, we left her bedroom light off for 10 days just to be sure….and no more smell.

    from some thread online?

    Thanks a million to those of you who helped us figure out what was causing the fishy smell in our bedroom (we had 100 watt bulbs in 40 watt sockets — whoops).

    The clients 2nd concern was possible mold at the dining room ceiling. She reported moisture damage and possible mold at the dining room ceiling, the moisture came from a past roof leak in the area. The client inspected what the client thought was mold and the inspector identified it as insect body parts. No mold or mold odors were found in this area. The attic directly above this area was clean and free of mold odors and visible mold and appeared unlikely to harbor unusual mold conditions. In the photo section the first photo is of the property, the 2nd is of the damaged dining room ceiling covered in plastic, and the 3rd is of the damage in the front guest bedroom. 

    ADDITIONAL OBSERVATIONS AND CONCLUSIONSThe inspector detected an extremely slight musty odor in the master bathroom. The inspector inspected under the floor of this bathroom in the crawl space two times and found no evidence of mold or moisture problems just slight musty odors. It appears that slight musty odors were from the moist soil under the trailer and were entering the bathroom through the hole in the bathroom floor where the toilets water supply pipe passes through the floor from the crawl space into the bathroom. Seal the opening where the toilet water supply pipes passes through the floor. 

    This inspector cannot inspect for hidden mold deep inside walls or hidden behind vapor barriers or insulation, the crawl space was not fully accessible as it was very small and ducts were in the way. Hidden mold may exist under the bathroom or in the bathroom walls but none was seen. A sample was taken from under the trailer in this odor and no unusual spore levels were found, it is likely that natural molds in the soils are releasing odors and these odors only and not the spores themselves were bypassing the vapor barrier where the sample was taken and then entering the bathroom. Destructive testing involving removal of walls and ducts and vapor barriers that were in the way and obstructing some view can be done if so desired, requested, and paid for.The trailers air was dusty as made evident when viewing the air samples and the indoor air was full of outdoor spores as was made evident when the samples were analyzed.

    The filter at the property is a inexpensive boars hair like filter and the client should use a pleated filter or a electrostatic filter to reduce indoor dust. Excessive outdoor spores in the house indicates to much outdoor air infiltrating the house, the house / trailer may be energy inefficient.

    Client should contact an exterminator because of lots of live fire ants in the side wall and under the carpet near the front windows.

 We Service The Following South Florida Counties And Cities:Miami Dade County Florida Mold Inspectors: Aventura, Bal Harbour, Bay Harbor Islands, Biscayne Park, Coconut Grove, Coral Gables, Cutler Ridge, Doral, El Portal, Florida City, Golden Isles, Goulds, Hialeah, Hieleah Gardens, Homestead, Indian Village, Islandia, Kendall, Key Biscayne, Leisure City, Medley, Miami Beach, Miami Gardens, Miami Lakes, Miami Shores Village, Miami Springs, North Bay Village, North Miami, North Miami Beach mold testing inspector, Opa-Locka, Princeton, Richmond Heights, South Miami, South Beach, Star Island, Fischer Island, Sunny Isles Beach, Surfside, Sweetwater, Virginia Gardens, West Miami house mold removal advice, Westchester, Westwood Lake Broward County Florida Mold Inspection, Deerfield, Ft Lauderdale, Lauderdale Lakes, Lauderhill, Hallandale, Pembroke Park, Oakland Park, Miramar, Pembroke Pines, Hollywood, Davie, Plantation, Weston, Fort. Lauderdale, Sunrise, Tamarac, Margate, Cooper City, Coral Springs, Parkland, Pompano toxic mold inspections, Lighthouse Point, Palm Beach County Florida Mold Testing,  West Palm Beach mold testing, Palm Beach, Boca Raton, Delray Beach, Lantana, Lake Worth, Boynton Beach, Wellington, West Palm Beach, Royal Palm Beach, Haverhill, Green Acres, Palm Beach Gardens, Jupiter, Juno Beach, Tequesta, North Palm Beach, Riviera Beach, Singer Island, Loxahatchee, Manalapan, Lake Clark Shores mold inspector, Mangonia Park, Belle Glade, Pahokee, Okeechobee, Indiantown, St Lucie County Mold Inspector, Ft. Pierce, Martin County commercial and residential building investigation help, Stuart, Hobe Sound, Port St Lucie, Jensen Beach Back mold removal help, Palm City, Port Salerno, Hutchinson Island. Monroe County Certified Florida Mold Inspector, Florida keys, Upper Keys, Lower Keys, Middle Keys, Key Largo, Islamorada, Key West.


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