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A/C coil corrosion - Chinese Drywall - US CPSC How to Find & Fix Sources of Sulphur Odors or Sewer-Gases, Rotten Egg Smells & Hazards in buildings

How to find and fix the source of sulphur odors and smells in buildings:

What might be causing sulphur odors or rotten egg smells in buildings? List of places to look when diagnosing the cause of sulphur smells or sewer gas smells in buildings.

This article and its companions discusse the common sources of rotten egg odors, sulphur odors or sewer gas smells in buildings and traces them to their possible cause.

Examples of sources of sulfur smells in or around buildings include Chinese drywall outgassing, dangerous sewer gas leaks, plumbing vent defects, sulfur in drinking water, water heater bacteria, and more. We describe safety, explosion, and bacterial hazards associated with sulphur gases and sewer gases in buildings.

Our page top photo shows a subtle clue that can explain a sulphur odor in buildings: discolored copper piping on the air conditioner cooling coil caused by outgassing from Chinese drywall.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

Q&A on how to Find & Ge Rid of Sulphur Odors or "Rotten Egg Smells" in buildings

Open sewer cleanout in basement (C) Daniel FriedmanThese questions & answers about diagnosing & fixing sulphur smells in buildings were posted originally

at SULPHUR & SEWER GAS SMELL SOURCES - be sure to review that article.

This article series about building odors discusses the diagnosis and cure of odors & smells from a variety of sources in and around buildings.

On 2018-04-29 by (mod) - rotten egg smell almost every day in my kitchen

First let's see if the odor has to do with your water supply: if that were the case, you'd smell the odor when running hot, cold, or both at every plumbing fixture in the home.

If that's not the case then we need to look for other odor sources. Let's start there. Let me know.

On 2018-04-29 by Bea

I smell rotten egg smell almost every day in my kitchen and have for months. I called the water dept. and they said it was not gas. But what can it be.

They said we have probably something in our complex underneath causing it.but not a solution ,I do not have gas appliances or heating,what other things can it be and who can fix it?

On 2018-03-08 by (mod) - cat flatulence - my cat smells like sulphur

Roy

A cat that has flatulence (excess gas, or if you'll pardon this effort at clarity: cat-farts) might smell like sulplhur.

Some cat illnesses (abscess, skin ailments, stool odors) might make your cat smell. That's a question to discuss with your cat's vet.

On 2018-03-08 by Roy

Can a recent rescue cat smell like sulphur on occasions

On 2018-02-18 18:45:42.068540 by Angela

Thank You very much I now know the difference and already contacted my consumers co. Just to be safe.

I think it's forced hot air I think that is what it's called

It's forced hot air & I have realized that most of the return air ducts had not been connected to the new furnace. The home is just over 2200 sq ft

Sorry it's a natural gas furnace only 5 1/2 yrs old.

On 2017-12-06 by (mod) - Heating systems don't usually make a sulphur smell

Heating systems don't usually make a sulphur smell but then, you don't mention the type of fuel.

If your heat is forced hot air, check for an odor source near the cold air returns.

Watch out: If your heat is gas fired the odor could mean that there is a very serious safety haxard such as a gas leak or combustion gases entering the building; be sure that your home has working CO and smoke detectors.

After that we're up to a heating service call.

That should include checking for LP gas or natural gas leaks.

On 2017-12-06 by Nance

I seem to be smelling a rotten egg smell occasionally when the heat goes on.

On 2017-10-11 22:08:52.653897 by (mod) -

Bea,

Indeed a failed water heater anode or bacterial contamination in a water heater can produce rotten egg smells.

On 2017-10-11 20:49:16.053923 by Bea

I have the rotten egg smell coming from my kitchen localized in one place under sink and electric water heater is located under that area.

I thought it was my garbage disposal and still think it is but have read several reasons and am concerned it may be dangerous. half a block away another person I know said they smelled the sulphur in their bathroom. I wonder if the city is responsible for some piping or other damage that may have broken or a leak in a sewer . I tried all the usual drain cleaning advice and it still smells .

On 2017-10-10 20:39:39.379760 by (mod) -

Look for an open plumbing vent first and a dead animal second

On 2017-10-09 15:25:50.611782 by Patricia

We have a very bad smell coming from the attic when we open the attic door its like rotten eggs. Does anyone know why this would be happening please ? we only moved in 4 weeks ago and its a new build

On 2016-11-05 19:44:24.087785 by Theresa

Our out door cat's head smells like sulfur. What could be the cause?

On 2016-08-15 00:58:26.708486 by (mod) -

IF your home uses Chinese-made interior drywall that might be a factor; but in general A/C refrigerant itself is odorless so you need to be looking for a different odor source: a dead animal in the ductwork, sewer gases being picked up and blown through ductwork (DANGEROUS, risking explosion).
See the list of sulphur odor sources in the article on this page.

On 2016-08-14 20:52:00.420312 by maat

I smell the affect of rotten eggs when I turn on the A/C, can anyone help? thank you.

On 2015-06-20 16:33:55.870960 by direction on stinky air from former garage sludge pump

Have a business in an 1898 former garage/auto delearship. Have odors coming up from what appears to be an old sludge pump. Have been told by old timers when garage closed oil pit was filled in with the oil still in it.

Cant find oil pit as concreted over but smell proliffice from sludge pump area. Is this dangerous and how can I check health concerns? Landlord no help, direction please as some mornings it make me have mild ashma, cant be good.

Question: sulphur stains on bathroom shower

Need to know if there is any product or natural way to remove or prevent stains from forming on the bathroom shower. - Anon 10/21/11

Reply:

Try installing a water treatment system that removes sulphur from the water supply is the most effective and general solution to an odor or sulphur (sulfur) related stain issue. I've found that for light staining on fixtures household cleaners work fine; for difficult stains, products intended to remove iron staining often seem to work well on black sulphur stains as well.

Question: smell in justy one room affects my throat; A/C system circulates it to other rooms

Last summer and again this summer every time we run out certral air conditioning unit there is a smell that permeates only one room in the house. the room above the unit. it is not natural gas becasue PSEand G was here and tested using their detector and found nothing.

The smell effcts my throat immediately. The system is cirulating the smell or is it causing the smell. Not everyone can smell it either, sometimes I smell it outside as well around the perimeter of the house, Please advise. Soould I call an air conditioning person or a plumber? - Anne Collins 7/7/2012

Reply:

Anne I would start with a careful inspection of that section of ductwork feeding the room where you smell the odor as well as the ceiling or wall cavity wherein the duct is routed. Check for a water or plumbing leak, mold, dead animal keep us posted.

Question: sulfur smell from faucet

How do you stop sulfur smell from faucet that is furthest away from water source (well)? The other faucets do not have the smel - Twinlaker 8/24/12

Reply:

Twinlaker,

Since the sulfur odor is not, by your account, in the water supply itself, just as you do, I suspect a more local source.

If you are dead sure that the smell comes from the water, and not from the building, walls, cavities, etc., nor from a drain in that room, then I suspect bacterial contamination of the plumbing fixtures;

Try shocking the well and through that procedure, the plumbing system in the home. Make sure to let the chlorinated water sit in the piping and faucet overnight, preferably 24 hours.

See WELL CHLORINATION & SHOCKING

Question: septic tank odor comes in my home

I have been gone all summer from Arizona and now I'm back how do I get the order to stop coming from the septic tank into my home. - Shirley 10/3/2012

Reply:

Shirley,

It is not proper nor normal operation for a septic tank to stink. If the odor is coming into your home from outside, the best fix is to inspect and diagnose the problem with the septic tank or drainfield and fix that source. Start your diagnosis at SEPTIC SYSTEM ODORS.

Question: how do we pinpoint the source of a rotten egg odor which comes and goes daily

We have a rotten egg odor which comes and goes daily, It is quite strong in the living room, but we cannot pinpoint it.Can it be coming from the back boiler central heating. /we have also picked up the odor in a kitchen cupboard where the electricity meter is,could something with the wiring be causing it.

My husband plumbed in a replacement sink about 6 months ago, and I complained about an odor. He fixed it, but could it be that.It's hard to detect the smell as we start to adjust to it. - Pamsie 10/26/2012

Reply:

Pamsie, the odor you describe is most often traced to a sewer gas or bad plumbing vent problem - which makes me suspect that the replacement sink may not be properly vented. But it sounds as if you need help tracking down the odor to its source. We provide quite a few suggestions for how to pinpoint an odor source in a separate article titled ODOR DIAGNOSIS CHECKLIST, PROCEDURE.

Question: pungent smell from Coleman split AC system in our trailer - coil cleaning?

(Apr 17, 2014) Dani said:
We have an old Coleman split system HVAC in our trailer. The heater & fan work fine, without odors or problems. But our AC is very weak & after it runs for 10-15 mins, a pungent smell is produced, comparable to brussel sprouts or rotten eggs.

We have brand new ducts, as of 6 mos ago. We replaced the filter & cleaned the coils, but the smell still persists. There is no condensation, if that means anything? We are going to go to Home Depot to get some coil cleaner stuff today. We live in Phoenix & we need our AC already!

Our trailer heats up fast, our thermostat reads 90 by 2-3pm! Any tips?

Reply:

If the coil is always in the air path, regardless of whether heating or cooling mode, one would expect that its effect on air flow would also always be present. Look at the evaporator (cooling) coil to see if it is blocked by dirt - if so that could explain weak air flow.

Odors might also be from quite a few other sources in ductwork: dead aninal, overheating electrical components or an odor being picked up from another building location via the return duct system.

Question: odors from leaky Carrier AC system - repairman said airborne sulfur caused leaks

(Nov 23, 2014) Anonymous said:

I bought a new Carrier A/C unit, in only 3 years the evaporator coils went bad and a small leak was detected, I notice some minor surface rust on the coil too. The evaporator coils are covered under warranty.

When I questioned the repairman he told me the ONLY thing that can cause this "rapid damage" to evaporator coil is the SULFUR in the air inside my home, the amount of moisture inside my home is drawn into my air-intake and the air mixed with SULFUR acts like a mild acid and destroys the evaporator coils.

Yes I do us well water but it runs thru a very expensive and well maintained water purification system, I have no rotten egg smell inside my home and my water smells and feels normal.

1. Does anyone who reads this agree with this mans theory?

2. Do you all think a BIG dehumidifier close to my air in-take will reduce the moisture in the air.

Reply:

(Nov 24, 2014) (mod) said:
Anon, I would not say ONLY sulphur in this case as there are other sources of corrosion such as Chinese drywall outgassing (discussed also at inspectApedia), swimming pool or other chlorine sources indoors, use of an inappropriate and corrosive cleaner on the coils, and even improper electrical grounding of the equipment.

See CHINESE DRYWALL HAZARDS & ODORS

Question: septic odors and frozen vent stack

(Jan 28, 2015) Colleen said:

We live in a rural area, have septic tank outside and underground and the sewage pump is in the basement.The tank is pumped out once a year. The last few years we have been getting sewage smell around the floor and hose holes that go from the sewage pump into the floor and back out to tank.

We have different plumbers look at it and cant figure it out, they have inspected tank had camera down drain etc..It seems like it most likely to occur after a few loads of laundry and not all the time.

Last year we had tank pumped and it didn't do it for 9 months, this year it started after a month.When they pumped tank last couple years the basement filled sewer gas, it came from the floor drain in the same room as the sewer pump and it has water in it..

Everything seems to drain and flush fine. We notice the vent stack on top the house seems to freeze more often than it did when the house was new it is 13 years old does anyone have any ideas please

Reply:

From your description it sounds as if slow drains or a failing septic mean that when a fair bit of water runs into the drain the slow drains are causing a push-out of sewer gas from the sewage pump reservoir.

If the vent stack is becoming blocked with frost that to could cause sewer gas (smelly and dangerous) to back up into the building. IN that case it may be possible to fix the problem by installing a larger vent stack up through the roof - when weather permits of course.

Did you ask your plumbers why you need openings from the sewer pump into the room and why the system isn't vented directly to outdoors? And are you saving up to replace the failing septic or broken drains?

Question: floor shakes and sewage smell in new office building

(Feb 16, 2015) Anonymous said:
work in a brand new office building.

This building has issue where the floor shakes really bad and the company is working to fix it...while they are fixing that...now all of a sudden it smells like raw sewage in here. It's daily and we are getting no answers from management. should a brand new office have this smell? It's a 4 story building. it's horrible to come to work in this stench.

Reply:

Anon: this complaint is not one that can be diagnosed by e-text. You need an on-site expert. But I can give an opinion that certainly you should not be smelling sewage gas indoors and that condition could be dangerous.

Question: outdoor air makes my kitchen surfaces and dishware smell like garbage

Apr 21, 2015) Frank said:
when the air from the outside come in my kitchen it makes my glasses,dishes , countertop ,sink, smell like garbage.could it be something in my home that's causing this problem,if I take a glass outside it will begin smelling also

Reply:

I can't make sense of this question, Frank. You need an on-site expert. First be sure that other people are verifying your complaint independently.


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